diff --git a/CMakeLists.txt b/CMakeLists.txt
index 2b324705..d8d7c572 100644
--- a/CMakeLists.txt
+++ b/CMakeLists.txt
@@ -2,13 +2,22 @@ cmake_minimum_required(VERSION 3.21 FATAL_ERROR)
 
 project(InChI C CXX)
 
+option(COVERAGE "Enable coverage reporting" OFF)
+
+if(COVERAGE)
+    message(STATUS "Building with code coverage enabled")
+    if(CMAKE_CXX_COMPILER_ID MATCHES "GNU|Clang")
+        add_compile_options(--coverage -O0 -g)
+        add_link_options(--coverage)
+    else()
+        message(WARNING "Coverage only supported with GCC or Clang")
+    endif()
+endif()
+
 set(CMAKE_C_STANDARD 99)
 set(CMAKE_CXX_STANDARD 11)
 set(CMAKE_POSITION_INDEPENDENT_CODE ON)
 
-# set(CMAKE_C_FLAGS "${CMAKE_C_FLAGS} -fsanitize=address")
-# set(CMAKE_CXX_FLAGS "${CMAKE_CXX_FLAGS} -fsanitize=address")
-
 include(FetchContent)
 FetchContent_Declare(
     googletest
@@ -26,3 +35,11 @@ add_subdirectory(INCHI-1-SRC/INCHI_EXE/inchi-1/src)
 add_subdirectory(INCHI-1-SRC/INCHI_API/libinchi/src)
 add_subdirectory(INCHI-1-TEST/tests/test_unit)
 
+if(COVERAGE)
+    add_custom_target(coverage
+        COMMAND ${CMAKE_CTEST_COMMAND} --output-on-failure
+        COMMAND find . -name '*.gcno' -exec gcov -b -c {} +
+        WORKING_DIRECTORY ${CMAKE_BINARY_DIR}
+        COMMENT "Running tests and generating .gcov coverage reports"
+    )
+endif()
diff --git a/INCHI-1-SRC/INCHI_API/libinchi/src/CMakeLists.txt b/INCHI-1-SRC/INCHI_API/libinchi/src/CMakeLists.txt
index 60f769ed..8fd3b273 100644
--- a/INCHI-1-SRC/INCHI_API/libinchi/src/CMakeLists.txt
+++ b/INCHI-1-SRC/INCHI_API/libinchi/src/CMakeLists.txt
@@ -5,11 +5,18 @@ project(LibInChI_API VERSION 1.7)
 add_library(libinchi_compiler_flags INTERFACE)
 target_compile_features(libinchi_compiler_flags INTERFACE c_std_11)
 
-set(gcc_like_cxx "$<COMPILE_LANG_AND_ID:C,ARMClang,AppleClang,Clang,GNU,LCC>")
-set(msvc_cxx "$<COMPILE_LANG_AND_ID:C,MSVC>")
+# set(gcc_like_cxx "$<COMPILE_LANG_AND_ID:C,ARMClang,AppleClang,Clang,GNU,LCC>")
+# set(msvc_cxx "$<COMPILE_LANG_AND_ID:C,MSVC>")
 target_compile_options(libinchi_compiler_flags INTERFACE
-	"$<${gcc_like_cxx}:$<BUILD_INTERFACE:-g;-O1;-c;-fno-strict-aliasing;-Wno-all>>"
-	"$<${msvc_cxx}:$<BUILD_INTERFACE:-W3;-MT;-O2>>"
+	# "$<$<CONFIG:Release>:<${gcc_like_cxx}:$<BUILD_INTERFACE:-g;-O1;-c;-fno-strict-aliasing;-Wno-all>>"
+	# "$<$<CONFIG:Release>:<${msvc_cxx}:$<BUILD_INTERFACE:-W3;-MT;-O2>>"
+	# "$<$<CONFIG:Debug>:<${gcc_like_cxx}:$<BUILD_INTERFACE:-g;-O0;-fsanitize=address;-c;-fno-strict-aliasing;-Wno-all>>"
+	# "$<$<CONFIG:Debug>:<${msvc_cxx}:$<BUILD_INTERFACE:-W3;-MT;-g;-O0;-fsanitize=address>>"
+
+    "$<$<AND:$<CONFIG:Release>,$<COMPILE_LANG_AND_ID:C,ARMClang,AppleClang,Clang,GNU,LCC>>:-g;-O1;-c;-fno-strict-aliasing;-Wno-all>"
+    "$<$<AND:$<CONFIG:Release>,$<COMPILE_LANG_AND_ID:C,MSVC>>:-W3;-MT;-O2>"
+    "$<$<AND:$<CONFIG:Debug>,$<COMPILE_LANG_AND_ID:C,ARMClang,AppleClang,Clang,GNU,LCC>>:-g;-O0;-fsanitize=address;-c;-fno-strict-aliasing;-Wno-all>"
+    "$<$<AND:$<CONFIG:Debug>,$<COMPILE_LANG_AND_ID:C,MSVC>>:-W3;-MT;-g;-O0>"
 )
 
 set(CMAKE_ARCHIVE_OUTPUT_DIRECTORY "${PROJECT_BINARY_DIR}/lib/static")
@@ -165,8 +172,12 @@ string(REGEX REPLACE "/RTC(su|[1su])" "" CMAKE_CXX_FLAGS_DEBUG "${CMAKE_CXX_FLAG
 set_target_properties(libinchi PROPERTIES PREFIX "")
 
 
+target_link_options(libinchi PRIVATE
+    "$<$<AND:$<CONFIG:Debug>,$<COMPILE_LANG_AND_ID:C,ARMClang,AppleClang,Clang,GNU,LCC>>:-fsanitize=address>"
+)
+
 if(UNIX AND NOT APPLE)
 	target_link_options(libinchi PRIVATE "LINKER:--version-script=${P_LIBINCHI_MAP}/libinchi.map,-z,relro")
 elseif(WIN32 AND NOT MSVC)
 	target_link_options(libinchi PRIVATE "LINKER:--version-script=${P_LIBINCHI_MAP}/libinchi.map")
-endif()
\ No newline at end of file
+endif()
diff --git a/INCHI-1-SRC/INCHI_BASE/src/ichi_io.c b/INCHI-1-SRC/INCHI_BASE/src/ichi_io.c
index 4c14a938..bcb40541 100644
--- a/INCHI-1-SRC/INCHI_BASE/src/ichi_io.c
+++ b/INCHI-1-SRC/INCHI_BASE/src/ichi_io.c
@@ -1679,7 +1679,7 @@ int inchi_strbuf_addline(INCHI_IOS_STRING* buf,
 /****************************************************************************/
 /* djb-rwth: placed as a global variable to avoid function buffer issues */
 char it_buffer[32767];
-int _inchi_trace(char* format, ...)
+int _inchi_trace(const char* format, ...)
 {
     /*
     TCHAR buffer[32767];
diff --git a/INCHI-1-SRC/INCHI_BASE/src/ichidrp.h b/INCHI-1-SRC/INCHI_BASE/src/ichidrp.h
index ff555c93..7e0e7673 100644
--- a/INCHI-1-SRC/INCHI_BASE/src/ichidrp.h
+++ b/INCHI-1-SRC/INCHI_BASE/src/ichidrp.h
@@ -187,6 +187,7 @@ typedef struct tagInputParms {
     int             bNoWarnings;            /* v. 1.06+ suppress warning messages                                   */
     int             bHideInChI;             /* v. 1.06+ Do not print InChI itself                                   */
 
+    int             bEnhancedStereo;
 
     /* */
     INCHI_MODE      bTautFlags;
diff --git a/INCHI-1-SRC/INCHI_BASE/src/ichimain.h b/INCHI-1-SRC/INCHI_BASE/src/ichimain.h
index 779d6b3e..c7f45018 100644
--- a/INCHI-1-SRC/INCHI_BASE/src/ichimain.h
+++ b/INCHI-1-SRC/INCHI_BASE/src/ichimain.h
@@ -125,7 +125,7 @@ typedef struct tagINCHI_OUT_CTL
     int iCurTautMode;
 
     int num_components;
-    int  nNumRemovedProtons;
+    int nNumRemovedProtons;
     int nTag;
     int bTag1;
     int bTag2;
diff --git a/INCHI-1-SRC/INCHI_BASE/src/ichimake.c b/INCHI-1-SRC/INCHI_BASE/src/ichimake.c
index 369133dc..0826571d 100644
--- a/INCHI-1-SRC/INCHI_BASE/src/ichimake.c
+++ b/INCHI-1-SRC/INCHI_BASE/src/ichimake.c
@@ -608,22 +608,21 @@ int GetSp3RelRacAbs(const INChI* pINChI, INChI_Stereo* Stereo)
                 nRet = SP3_REL;
 #endif
             }
-            else
-                if (pINChI->nFlags & INCHI_FLAG_RAC_STEREO)
-                {
+            else if (pINChI->nFlags & INCHI_FLAG_RAC_STEREO)
+            {
 #if ( REL_RAC_STEREO_IGN_1_SC == 1 )
-                    if (1 < Stereo->nNumberOfStereoCenters)
-                    {
-                        nRet = SP3_REL;
-                    }
-#else
-                    nRet = SP3_RAC;
-#endif
-                }
-                else
+                if (1 < Stereo->nNumberOfStereoCenters)
                 {
-                    nRet = SP3_ABS;
+                    nRet = SP3_REL;
                 }
+#else
+                nRet = SP3_RAC;
+#endif
+            }
+            else
+            {
+                nRet = SP3_ABS;
+            }
         }
         else
 #if ( REL_RAC_STEREO_IGN_1_SC == 1 )
diff --git a/INCHI-1-SRC/INCHI_BASE/src/ichimake.h b/INCHI-1-SRC/INCHI_BASE/src/ichimake.h
index 4f7f9db5..fd35db2a 100644
--- a/INCHI-1-SRC/INCHI_BASE/src/ichimake.h
+++ b/INCHI-1-SRC/INCHI_BASE/src/ichimake.h
@@ -208,6 +208,20 @@ const char *EquString( int EquVal );
                           INCHI_IOS_STRING *buf,
                           int nCtMode,
                           int *bOverflow );
+    int MakeEnhStereoString( INChI_Aux        *pAux,
+                             INCHI_IOS_STRING *strbuf,
+                             const char*      conf_stereo_string,
+                             int              **enh_stereo,
+                             int              nof_stereo_groups,
+                             int              nCtMode,
+                             int              *bOverflow );
+    int MakeSlayerString( ORIG_ATOM_DATA   *orig_inp_data,
+                          INCHI_SORT       *pINChISort,
+                          INCHI_IOS_STRING *strbuf,
+                          int              bOutType,
+                          int              num_components,
+                          int              nCtMode,
+                          int              *bOverflow );
     int MakeCRVString( ORIG_INFO *OrigInfo,
                        int nLenCT,
                        int bAddDelim,
diff --git a/INCHI-1-SRC/INCHI_BASE/src/ichiparm.c b/INCHI-1-SRC/INCHI_BASE/src/ichiparm.c
index bfa14414..dcf4d9b8 100644
--- a/INCHI-1-SRC/INCHI_BASE/src/ichiparm.c
+++ b/INCHI-1-SRC/INCHI_BASE/src/ichiparm.c
@@ -122,7 +122,8 @@ int set_common_options_by_parg(const char* pArg,
     int* pbNPZz,
     int* pbNoWarnings,
     int* pbMergeHash,
-    int* pbHideInChI);
+    int* pbHideInChI,
+    int* pbEnhancedStereochemistry);
 
 
 /****************************************************************************
@@ -165,7 +166,8 @@ int set_common_options_by_parg(const char* pArg,
     int* pbNPZz,
     int* pbNoWarnings,
     int* pbMergeHash,
-    int* pbHideInChI
+    int* pbHideInChI,
+    int* pbEnhancedStereochemistry
 )
 {
     int got = 0;
@@ -266,6 +268,11 @@ int set_common_options_by_parg(const char* pArg,
         (*pbLooseTSACheck) = 1;
         got = 1;
     }
+    else if (!inchi_stricmp(pArg, "EnhancedStereochemistry"))
+    {
+        *pbEnhancedStereochemistry = 1;
+        got = 1;
+    }
 
 #ifndef USE_STDINCHI_API
     /* These options DO TURN OFF Std flag   */
@@ -643,6 +650,7 @@ int ReadCommandLineParms(int argc,
     int bAcidTautomerism = (DISCONNECT_SALTS == 1) ? (TEST_REMOVE_S_ATOMS == 1 ? 2 : 1) : 0;
     int bUnchargedAcidTaut = (CHARGED_SALTS_ONLY == 0);
     int bMergeSaltTGroups = (DISCONNECT_SALTS == 1);
+    int bEnhancedStereochemistry = 0;
 #if ( MIN_SB_RING_SIZE > 0 )
     int nMinDbRinSize = MIN_SB_RING_SIZE, mdbr = 0;
 #endif
@@ -795,7 +803,8 @@ int ReadCommandLineParms(int argc,
                 &bLargeMolecules, &bPolymers,
                 &bFoldPolymerSRU, &bFrameShiftScheme,
                 &bStereoAtZz, &bNPZz,
-                &bNoWarnings, &bMergeHash, &bHideInChI);
+                &bNoWarnings, &bMergeHash, &bHideInChI,
+                &bEnhancedStereochemistry);
             if (got)
             {
                 ;
@@ -1243,7 +1252,8 @@ int ReadCommandLineParms(int argc,
                 &bLargeMolecules, &bPolymers,
                 &bFoldPolymerSRU, &bFrameShiftScheme,
                 &bStereoAtZz, &bNPZz,
-                &bNoWarnings, &bMergeHash, &bHideInChI);
+                &bNoWarnings, &bMergeHash, &bHideInChI,
+                &bEnhancedStereochemistry);
 
             if (got)
             {
@@ -2120,6 +2130,8 @@ int ReadCommandLineParms(int argc,
 
     ip->bINChIOutputOptions2 = bINChIOutputOptions2;
 
+    ip->bEnhancedStereo = bEnhancedStereochemistry;
+
     return 0;
 }
 
diff --git a/INCHI-1-SRC/INCHI_BASE/src/ichiprt1.c b/INCHI-1-SRC/INCHI_BASE/src/ichiprt1.c
index 0547b3e5..0ee22261 100644
--- a/INCHI-1-SRC/INCHI_BASE/src/ichiprt1.c
+++ b/INCHI-1-SRC/INCHI_BASE/src/ichiprt1.c
@@ -129,6 +129,13 @@ static int OutputINCHI_StereoLayer( CANON_GLOBALS *pCG,
                                     INCHI_OUT_CTL *io,
                                     char *pLF,
                                     char *pTAB );
+static int OutputINCHI_StereoLayer_EnhancedStereo( CANON_GLOBALS *pCG,
+                                                   INCHI_IOSTREAM *out_file,
+                                                   INCHI_IOS_STRING *strbuf,
+                                                   INCHI_OUT_CTL *io,
+                                                   ORIG_ATOM_DATA *orig_inp_data,
+                                                   char *pLF,
+                                                   char *pTAB );
 static int OutputINCHI_IsotopicLayer( CANON_GLOBALS *pCG,
                                       INCHI_IOSTREAM *out_file,
                                       INCHI_IOS_STRING *strbuf,
@@ -150,11 +157,11 @@ static int OutputINCHI_PolymerLayer( CANON_GLOBALS *pCG, INCHI_IOSTREAM *out_fil
                                      INCHI_OUT_CTL *io, char *pLF, char *pTAB );
 static int OutputINCHI_PolymerLayer_SingleUnit( OAD_PolymerUnit *u,
                                                 int bPolymers,
-                                                int total_star_atoms, 
+                                                int total_star_atoms,
                                                 int *n_used_stars,
-                                                OAD_AtProps *aprops, 
+                                                OAD_AtProps *aprops,
                                                 int *cano_nums,
-                                                ORIG_ATOM_DATA *orig_inp_data, 
+                                                ORIG_ATOM_DATA *orig_inp_data,
                                                 ORIG_STRUCT *pOrigStruct,
                                                 INCHI_IOS_STRING *strbuf );
 static int OutputAUXINFO_HeaderAndNormalization_type( CANON_GLOBALS *pCG,
@@ -1032,14 +1039,29 @@ int OutputINChI2( CANON_GLOBALS     *pCG,
     return ret;
 }
 
-
-/*                                                          */
-/*    OutputINChI1( ... )                                   */
-/*                                                          */
-/*    Main actual worker which serializes InChI to string.  */
-/*                                                          */
-/*    Called from OutputINChI2( ... ) and from itself       */
-/*                                                          */
+/**
+ * @brief Main actual worker which serializes InChI to string. Called from OutputINChI2( ... ) and from itself.
+ *
+ * @param pCG Pointer to global canonicalization data.
+ * @param strbuf Pointer to the output string buffer.
+ * @param pINChISortTautAndNonTaut2 Array of pointers to INCHI_SORT structures for tautomeric and non-tautomeric forms.
+ * @param INCHI_basic_or_INCHI_reconnected Flag indicating basic or reconnected InChI output.
+ * @param orig_inp_data Pointer to original atom data.
+ * @param pOrigStruct Pointer to the original structure data.
+ * @param ip Pointer to input parameters.
+ * @param bDisconnectedCoord Flag for disconnected metal coordination.
+ * @param bOutputType Output type (tautomeric/non-tautomeric/both).
+ * @param bINChIOutputOptions Bitmask of output options.
+ * @param num_components2 Array of component counts for each structure type.
+ * @param num_non_taut2 Array of non-tautomeric component counts.
+ * @param num_taut2 Array of tautomeric component counts.
+ * @param out_file Output stream for InChI string.
+ * @param log_file Output stream for logging.
+ * @param num_input_struct Number of input structures.
+ * @param pSortPrintINChIFlags Pointer to flags controlling sorting and printing.
+ * @param save_opt_bits Encoded bits for saved InChI creation options.
+ * @return int
+ */
 int OutputINChI1( CANON_GLOBALS *pCG,
                   INCHI_IOS_STRING *strbuf,
                   INCHI_SORT *pINChISortTautAndNonTaut2[][TAUT_NUM],
@@ -1160,7 +1182,7 @@ int OutputINChI1( CANON_GLOBALS *pCG,
             io.n_pzz = orig_inp_data->polymer->n_pzz;
         }
     }
-    
+
 
     io.bPolymers = ip->bPolymers;
 
@@ -1615,6 +1637,11 @@ int OutputINChI1( CANON_GLOBALS *pCG,
                         io.bChargesRadVal[ii] |= 1;
                     }
                 }
+
+                if (ip->bEnhancedStereo)
+                {
+                    set_EnhancedStereo_t_m_layers(orig_inp_data, pINChI, pINChI_Aux);
+                }
             }
         }
         if (bCompExists)
@@ -1701,6 +1728,10 @@ int OutputINChI1( CANON_GLOBALS *pCG,
         {
             is_beta = 1;
         }
+        else if (ip->bEnhancedStereo)
+        {
+            is_beta = 1;
+        }
 
         OutputINCHI_VersionAndKind( out_file, strbuf, bINChIOutputOptions, is_beta, pLF, pTAB );
     }
@@ -1753,7 +1784,11 @@ int OutputINChI1( CANON_GLOBALS *pCG,
     }
 
     /* InChI output: stereo (non-isotopic) */
-    intermediate_result = OutputINCHI_StereoLayer( pCG, out_file, strbuf, &io, pLF, pTAB );
+    if (ip->bEnhancedStereo) {
+        intermediate_result = OutputINCHI_StereoLayer_EnhancedStereo( pCG, out_file, strbuf, &io, orig_inp_data, pLF, pTAB );
+    } else {
+        intermediate_result = OutputINCHI_StereoLayer( pCG, out_file, strbuf, &io, pLF, pTAB );
+    }
     if (intermediate_result != 0)
         goto exit_function;
 
@@ -2640,7 +2675,7 @@ int WriteOrigBonds( CANON_GLOBALS *pCG,
             num_trans = 0; /* djb-rwth: ignoring LLVM warning: variable used to store function return value */
             nNeighOrder[0] = 0;
         }
-        for (kk = 0; kk < at[j].valence; kk++) 
+        for (kk = 0; kk < at[j].valence; kk++)
         {
             k = nNeighOrder[kk];
             j2 = at[j].neighbor[k];
@@ -3121,7 +3156,7 @@ void set_line_separators( int bINChIOutputOptions, char **pLF, char **pTAB )
         int  bPlainTabbedOutput = 0 != ( bINChIOutputOptions & INCHI_OUT_TABBED_OUTPUT ) &&
             bPlainText && !bPlainTextCommnts;
 
-        *pTAB = bPlainTabbedOutput ? "\t" : "\n";
+        *pTAB = bPlainTabbedOutput ? (char*)"\t" : (char*)"\n";
     }
 #else
     *pTAB = "\n";
@@ -3347,10 +3382,17 @@ int OutputINCHI_ChargeAndRemovedAddedProtonsLayers( CANON_GLOBALS    *pCG,
     return 0;
 }
 
-
-/****************************************************************************
-Output InChI: stereo layer with sublayers
-****************************************************************************/
+/**
+ * @brief Output InChI: stereo layer with sublayers.
+ *
+ * @param pCG Pointer to the CANON_GLOBALS structure containing global canonicalization data.
+ * @param out_file Pointer to the INCHI_IOSTREAM output stream where the stereo layer will be written.
+ * @param strbuf Pointer to an INCHI_IOS_STRING buffer used for string formatting and output.
+ * @param io Pointer to the INCHI_OUT_CTL structure containing output control and state information.
+ * @param pLF Pointer to a string used as the line feed (end-of-line) character(s).
+ * @param pTAB Pointer to a string used as the tab or separator character(s).
+ * @return Returns 0 on success, or a non-zero error code on failure.
+ */
 int OutputINCHI_StereoLayer( CANON_GLOBALS    *pCG,
                              INCHI_IOSTREAM   *out_file,
                              INCHI_IOS_STRING *strbuf,
@@ -3359,16 +3401,10 @@ int OutputINCHI_StereoLayer( CANON_GLOBALS    *pCG,
                              char             *pTAB )
 {
 
-    {
-        int i;
-        i = INChI_SegmentAction( io->sDifSegs[io->nCurINChISegment][DIFS_t_SATOMS] ); /* djb-rwth: ignoring LLVM warning: variable used to store function return value */
-        /* djb-rwth: removing redundant code */
-    }
-
     if (INChI_SegmentAction( io->sDifSegs[io->nCurINChISegment][DIFS_b_SBONDS] ) ||
-         INChI_SegmentAction( io->sDifSegs[io->nCurINChISegment][DIFS_t_SATOMS] ) ||
-         INChI_SegmentAction( io->sDifSegs[io->nCurINChISegment][DIFS_m_SP3INV] ) ||
-         INChI_SegmentAction( io->sDifSegs[io->nCurINChISegment][DIFS_s_STYPE] ))
+        INChI_SegmentAction( io->sDifSegs[io->nCurINChISegment][DIFS_t_SATOMS] ) ||
+        INChI_SegmentAction( io->sDifSegs[io->nCurINChISegment][DIFS_m_SP3INV] ) ||
+        INChI_SegmentAction( io->sDifSegs[io->nCurINChISegment][DIFS_s_STYPE] ))
     {
 
         /*  stereo */
@@ -3377,8 +3413,7 @@ int OutputINCHI_StereoLayer( CANON_GLOBALS    *pCG,
 
         /*  sp2 */
 
-        /*if ( bStereoSp2[io->iCurTautMode]  )*/
-        if ((io->nSegmAction = INChI_SegmentAction( io->sDifSegs[io->nCurINChISegment][DIFS_b_SBONDS] ))) /* djb-rwth: addressing LLVM warning */
+        if ((io->nSegmAction = INChI_SegmentAction( io->sDifSegs[io->nCurINChISegment][DIFS_b_SBONDS] )))
         {
             szGetTag( IdentLbl, io->nTag, io->bTag2 = io->bTag1 | IL_DBND, io->szTag2, &io->bAlways, 1 );
             inchi_strbuf_reset( strbuf );
@@ -3386,8 +3421,8 @@ int OutputINCHI_StereoLayer( CANON_GLOBALS    *pCG,
             if (INCHI_SEGM_FILL == io->nSegmAction)
             {
                 io->tot_len = str_Sp2( io->pINChISort, io->pINChISort2, strbuf, &io->bOverflow,
-                                        io->bOutType, io->TAUT_MODE, io->num_components,
-                                        io->bSecondNonTautPass, io->bOmitRepetitions, io->bUseMulipliers );
+                                       io->bOutType, io->TAUT_MODE, io->num_components,
+                                       io->bSecondNonTautPass, io->bOmitRepetitions, io->bUseMulipliers );
 
                 io->bNonTautNonIsoIdentifierNotEmpty += io->bSecondNonTautPass;
             }
@@ -3408,7 +3443,7 @@ int OutputINCHI_StereoLayer( CANON_GLOBALS    *pCG,
 
         /*  sp3 */
 
-        /*if ( bStereoSp3[io->iCurTautMode]  )*/
+        /* t-layer */
         if ((io->nSegmAction = INChI_SegmentAction( io->sDifSegs[io->nCurINChISegment][DIFS_t_SATOMS] ))) /* djb-rwth: addressing LLVM warning */
         {
             io->bRelRac = io->bRelativeStereo[io->iCurTautMode] || io->bRacemicStereo[io->iCurTautMode];
@@ -3419,7 +3454,7 @@ int OutputINCHI_StereoLayer( CANON_GLOBALS    *pCG,
             {
                 io->tot_len = str_Sp3( io->pINChISort, io->pINChISort2, strbuf, &io->bOverflow,
                                        io->bOutType, io->TAUT_MODE, io->num_components, io->bRelRac,
-                                   io->bSecondNonTautPass, io->bOmitRepetitions, io->bUseMulipliers );
+                                       io->bSecondNonTautPass, io->bOmitRepetitions, io->bUseMulipliers );
 
                 io->bNonTautNonIsoIdentifierNotEmpty += io->bSecondNonTautPass;
             }
@@ -3432,12 +3467,13 @@ int OutputINCHI_StereoLayer( CANON_GLOBALS    *pCG,
         }
         else
         {
-            if (io->bPlainTextTags == 1) inchi_ios_print_nodisplay( out_file, "/" ); /* sp3 */
+            if (io->bPlainTextTags == 1)
+            {
+                inchi_ios_print_nodisplay( out_file, "/" ); /* sp3 */
+            }
         }
 
-        /* bStereoAbsInverted[io->iCurTautMode]  */
-
-        /* if ( bStereoAbs[io->iCurTautMode]  ) */
+        /* m-layer */
         if ((io->nSegmAction = INChI_SegmentAction( io->sDifSegs[io->nCurINChISegment][DIFS_m_SP3INV] ))) /* djb-rwth: addressing LLVM warning */
         {
             szGetTag( IdentLbl, io->nTag, io->bTag2 = io->bTag1 | IL_INVS, io->szTag2, &io->bAlways, 1 );
@@ -3445,7 +3481,7 @@ int OutputINCHI_StereoLayer( CANON_GLOBALS    *pCG,
             if (INCHI_SEGM_FILL == io->nSegmAction)
             {
                 io->tot_len = str_StereoAbsInv( io->pINChISort, strbuf,
-                                            &io->bOverflow, io->bOutType, io->num_components );
+                                               &io->bOverflow, io->bOutType, io->num_components );
                 io->bNonTautNonIsoIdentifierNotEmpty += io->bSecondNonTautPass;
             }
 
@@ -3465,8 +3501,8 @@ int OutputINCHI_StereoLayer( CANON_GLOBALS    *pCG,
 
         /* stereo type */
 
-        /*if ( io->bRacemicStereo[io->iCurTautMode] || io->bRelativeStereo[io->iCurTautMode] || bStereoAbs[io->iCurTautMode] )*/
-        if ((io->nSegmAction = INChI_SegmentAction( io->sDifSegs[io->nCurINChISegment][DIFS_s_STYPE] ))) /* djb-rwth: addressing LLVM warning */
+        /* s-layer */
+        if ((io->nSegmAction = INChI_SegmentAction( io->sDifSegs[io->nCurINChISegment][DIFS_s_STYPE] )))
         {
             const char *p_stereo = io->bRelativeStereo[io->iCurTautMode] ? x_rel :
                 io->bRacemicStereo[io->iCurTautMode] ? x_rac : x_abs;
@@ -3490,15 +3526,193 @@ int OutputINCHI_StereoLayer( CANON_GLOBALS    *pCG,
     }
     else
     {
-        if (io->bPlainTextTags == 1) inchi_ios_print_nodisplay( out_file, "////" ); /* sp3, sp2, abs-inv, stereo.type */
+        if (io->bPlainTextTags == 1)
+        {
+            inchi_ios_print_nodisplay( out_file, "////" ); /* sp2, sp3, abs-inv, stereo.type */
+        }
     }
 
     return 0;
 }
 
+/**
+ * @brief Output InChI: stereo layer with sublayers for enhanced stereochemistry (absolute, relative, racemic).
+ *
+ * @param pCG Pointer to the CANON_GLOBALS structure containing global canonicalization data.
+ * @param out_file Pointer to the INCHI_IOSTREAM output stream where the stereo layer will be written.
+ * @param strbuf Pointer to an INCHI_IOS_STRING buffer used for string formatting and output.
+ * @param io Pointer to the INCHI_OUT_CTL structure containing output control and state information.
+ * @param orig_inp_data Pointer to the ORIG_ATOM_DATA containing e.g. atom information.
+ * @param pLF Pointer to a string used as the line feed (end-of-line) character(s).
+ * @param pTAB Pointer to a string used as the tab or separator character(s).
+ * @return Returns 0 on success, or a non-zero error code on failure.
+ */
+int OutputINCHI_StereoLayer_EnhancedStereo(
+        CANON_GLOBALS    *pCG,
+        INCHI_IOSTREAM   *out_file,
+        INCHI_IOS_STRING *strbuf,
+        INCHI_OUT_CTL    *io,
+        ORIG_ATOM_DATA   *orig_inp_data,
+        char             *pLF,
+        char             *pTAB )
+{
+
+    if (INChI_SegmentAction( io->sDifSegs[io->nCurINChISegment][DIFS_b_SBONDS] ) ||
+        INChI_SegmentAction( io->sDifSegs[io->nCurINChISegment][DIFS_t_SATOMS] ) ||
+        INChI_SegmentAction( io->sDifSegs[io->nCurINChISegment][DIFS_m_SP3INV] ) ||
+        INChI_SegmentAction( io->sDifSegs[io->nCurINChISegment][DIFS_s_STYPE] ))
+    {
+
+        /*  stereo */
+
+        szGetTag( IdentLbl, io->nTag, io->bTag1 = IL_STER | io->bFhTag, io->szTag1, &io->bAlways, 1 );
+
+        /*  sp2 */
+
+        if ((io->nSegmAction = INChI_SegmentAction( io->sDifSegs[io->nCurINChISegment][DIFS_b_SBONDS] )))
+        {
+            szGetTag( IdentLbl, io->nTag, io->bTag2 = io->bTag1 | IL_DBND, io->szTag2, &io->bAlways, 1 );
+            inchi_strbuf_reset( strbuf );
+            io->tot_len = 0;
+            if (INCHI_SEGM_FILL == io->nSegmAction)
+            {
+                io->tot_len = str_Sp2( io->pINChISort, io->pINChISort2, strbuf, &io->bOverflow,
+                                       io->bOutType, io->TAUT_MODE, io->num_components,
+                                       io->bSecondNonTautPass, io->bOmitRepetitions, io->bUseMulipliers );
+
+                io->bNonTautNonIsoIdentifierNotEmpty += io->bSecondNonTautPass;
+            }
+
+            if (str_LineEnd( io->szTag2, &io->bOverflow, strbuf, -io->nSegmAction, io->bPlainTextTags ))
+            {
+                return 1;
+            }
+            inchi_ios_print_nodisplay( out_file, "%s%s", strbuf->pStr, pLF );
+        }
+        else
+        {
+            if (io->bPlainTextTags == 1)
+            {
+                inchi_ios_print_nodisplay( out_file, "/" ); /* sp2 */
+            }
+        }
+
+        /*  sp3 */
+
+        /* t-layer */
+        if ((io->nSegmAction = INChI_SegmentAction( io->sDifSegs[io->nCurINChISegment][DIFS_t_SATOMS] ))) /* djb-rwth: addressing LLVM warning */
+        {
+            io->bRelRac = io->bRelativeStereo[io->iCurTautMode] || io->bRacemicStereo[io->iCurTautMode];
+            szGetTag( IdentLbl, io->nTag, io->bTag2 = io->bTag1 | IL_SP3S, io->szTag2, &io->bAlways, 1 );
+            inchi_strbuf_reset( strbuf );
+            io->tot_len = 0;
+            if (INCHI_SEGM_FILL == io->nSegmAction)
+            {
+                io->tot_len = str_Sp3( io->pINChISort, io->pINChISort2, strbuf, &io->bOverflow,
+                                       io->bOutType, io->TAUT_MODE, io->num_components, io->bRelRac,
+                                       io->bSecondNonTautPass, io->bOmitRepetitions, io->bUseMulipliers );
+
+                io->bNonTautNonIsoIdentifierNotEmpty += io->bSecondNonTautPass;
+            }
+
+            if (str_LineEnd( io->szTag2, &io->bOverflow, strbuf, -io->nSegmAction, io->bPlainTextTags ))
+            {
+                return 2;
+            }
+            inchi_ios_print_nodisplay( out_file, "%s%s", strbuf->pStr, pLF );
+        }
+        else
+        {
+            if (io->bPlainTextTags == 1)
+            {
+                inchi_ios_print_nodisplay( out_file, "/" ); /* sp3 */
+            }
+        }
+
+        /* m-layer */
+        if ((io->nSegmAction = INChI_SegmentAction( io->sDifSegs[io->nCurINChISegment][DIFS_m_SP3INV] ))) /* djb-rwth: addressing LLVM warning */
+        {
+            szGetTag( IdentLbl, io->nTag, io->bTag2 = io->bTag1 | IL_INVS, io->szTag2, &io->bAlways, 1 );
+            inchi_strbuf_reset( strbuf );
+            io->tot_len = 0;
+            if (INCHI_SEGM_FILL == io->nSegmAction)
+            {
+                io->tot_len = str_StereoAbsInv( io->pINChISort, strbuf,
+                                               &io->bOverflow, io->bOutType, io->num_components );
+                io->bNonTautNonIsoIdentifierNotEmpty += io->bSecondNonTautPass;
+            }
+
+            if (str_LineEnd( io->szTag2, &io->bOverflow, strbuf, -io->nSegmAction, io->bPlainTextTags ))
+            {
+                return 3;
+            }
+            inchi_ios_print_nodisplay( out_file, "%s%s", strbuf->pStr, pLF );
+        }
+        else
+        {
+            if (io->bPlainTextTags == 1)
+            {
+                inchi_ios_print_nodisplay( out_file, "/" ); /* stereo-abs-inv */
+            }
+        }
+
+        /* stereo type */
+
+        /* s-layer */
+        if ((io->nSegmAction = INChI_SegmentAction( io->sDifSegs[io->nCurINChISegment][DIFS_s_STYPE] )))
+        {
+            const char *p_stereo = io->bRelativeStereo[io->iCurTautMode] ? x_rel :
+                io->bRacemicStereo[io->iCurTautMode] ? x_rac : x_abs;
+
+            szGetTag( IdentLbl, io->nTag, io->bTag2 = io->bTag1 | IL_TYPS, io->szTag2, &io->bAlways, 1 );
+            inchi_strbuf_reset( strbuf ); io->tot_len = 0;
+
+            io->tot_len = 0;
+            if (INCHI_SEGM_FILL == io->nSegmAction)
+            {
+                if (orig_inp_data->v3000->n_steabs > 0 ||
+                    orig_inp_data->v3000->n_sterel > 0 ||
+                    orig_inp_data->v3000->n_sterac > 0) {
+                    io->tot_len += MakeSlayerString(
+                        orig_inp_data,
+                        io->pINChISort,
+                        strbuf,
+                        io->bOutType,
+                        io->num_components,
+                        io->TAUT_MODE,
+                        &io->bOverflow
+                    );
+                } else {
+                    ( io->tot_len ) += MakeDelim( p_stereo, strbuf, &io->bOverflow );
+                }
+
+                io->bNonTautNonIsoIdentifierNotEmpty += io->bSecondNonTautPass;
+            }
+            if (str_LineEnd( io->szTag2, &io->bOverflow, strbuf, -io->nSegmAction, io->bPlainTextTags ))
+            {
+                return 1;
+            }
+            inchi_ios_print_nodisplay( out_file, "%s%s", strbuf->pStr, pLF );
+        }
+        if (io->bPlainTextTags == 1)
+        {
+            inchi_ios_print_nodisplay( out_file, "/" );  /* no abs, inv or racemic stereo */
+        }
+    }
+    else
+    {
+        if (io->bPlainTextTags == 1)
+        {
+            inchi_ios_print_nodisplay( out_file, "////" ); /* sp2, sp3, abs-inv, stereo.type */
+        }
+    }
+
+    return 0;
+}
 
 /****************************************************************************
-Output InChI: isotopic layer and sublayers  ****************************************************************************/
+Output InChI: isotopic layer and sublayers
+****************************************************************************/
 int OutputINCHI_IsotopicLayer( CANON_GLOBALS    *pCG,
                                INCHI_IOSTREAM   *out_file,
                                INCHI_IOS_STRING *strbuf,
@@ -3908,7 +4122,7 @@ static int OutputINCHI_PolymerLayer( CANON_GLOBALS *pCG,
     nat = orig_inp_data->num_inp_atoms;
     num_inp_bonds = orig_inp_data->num_inp_bonds;
 
-    
+
     if (pOrigStruct && !pOrigStruct->polymer)
     {
         return 0;
@@ -4145,7 +4359,7 @@ static int OutputINCHI_PolymerLayer_SingleUnit( OAD_PolymerUnit *u,
         a2 = u->blist[1];
         a3 = u->blist[2];
         a4 = u->blist[3];
-        
+
         if (is_in_the_ilist( u->alist, a1, u->na ))
         {
             tmp = a2;
@@ -4172,7 +4386,7 @@ static int OutputINCHI_PolymerLayer_SingleUnit( OAD_PolymerUnit *u,
             /* The first printed is the crossing bond pointing to more senior CRU end ("head")    */
             swap = (OAD_Polymer_IsFirstAtomRankLower(a2, a4, aprops) == 1);
         }
-        
+
         if (swap)
         {
             inchi_strbuf_printf( strbuf, "(%-d-%-d,%-d-%-d)", a3, a4, a1, a2 );
@@ -4288,8 +4502,8 @@ static int OutputINCHI_PolymerLayer_SingleUnit( OAD_PolymerUnit *u,
                         here
                         at1, at2 is the most senior bond, and at1 is more senior than at2
                         all other pairs at3,at4,  at5,at6, ... are sorted just in increasing
-                        order of first number in pair, then second one, e.g.: at3<at4; at3<=at5 
-                        (and if at3==at5 then at4<at6) 
+                        order of first number in pair, then second one, e.g.: at3<at4; at3<=at5
+                        (and if at3==at5 then at4<at6)
                     */
 
                     if (p->frame_shift_scheme != FSS_NONE && u->nbkbonds >= 1 && u->cap1 >= 1 && u->cap2 >= 1)
@@ -5046,7 +5260,7 @@ void EditINCHI_HidePolymerZz(INCHI_IOSTREAM *out, int n_pzz, int n_zy)
         eol_was_consumed = 0, pre_eol = 0,
         nonprt_sym = 0, nonprt_prev = 0;
 
-    if (n_zy > 0) 
+    if (n_zy > 0)
     {
         /* We have some placeholder pseudo atoms which should not be removed below (if anyway they are allowed) */
         if (n_pzz == 0)
@@ -5131,7 +5345,7 @@ void EditINCHI_HidePolymerZz(INCHI_IOSTREAM *out, int n_pzz, int n_zy)
                 AT_NUMB ia = (AT_NUMB) inchi_strtol(p, &q, 10); /* make compiler happy: */ /* djb-rwth: removing redundant code; ignoring LLVM warning: variable used to store function return value */
                 if (*q != '-')
                 {
-                    skip = 1; 
+                    skip = 1;
                 }
             }
         }
@@ -5283,7 +5497,7 @@ int CountPseudoElementInFormula( const char *pseudo, char *s ) /* djb-rwth: igno
     char prev = '/';
 
     /*
-        format is 
+        format is
         [sequence of] [.[int_mult[Zz[int_index]]]]
     */
 
@@ -5291,8 +5505,8 @@ int CountPseudoElementInFormula( const char *pseudo, char *s ) /* djb-rwth: igno
     {
         return 0;
     }
-    
-    p = s; 
+
+    p = s;
     while (*p)
     /*for (p = s ; *p; p++)*/
     {
@@ -5317,7 +5531,7 @@ int CountPseudoElementInFormula( const char *pseudo, char *s ) /* djb-rwth: igno
             {
                 mult = (int)inchi_strtol(p, &q, 10);
                 p = q;
-                prev = *q--; 
+                prev = *q--;
                 continue;
             }
             else
@@ -5326,7 +5540,7 @@ int CountPseudoElementInFormula( const char *pseudo, char *s ) /* djb-rwth: igno
             }
             if (!mult)
             {
-                break; 
+                break;
             }
         }
         else if (*p== pseudo[1] && prev== pseudo[0])
@@ -5446,7 +5660,7 @@ int MergeZzInHillFormula(INCHI_IOS_STRING *strbuf)
     {
         inchi_free(scopy); /* djb-rwth: avoiding memory leak */
         return -1; /* failed */
-    }    
+    }
     memcpy(scopy, strbuf->pStr, strbuf->nAllocatedLength);
     stmp = (char *)inchi_calloc((long long)strbuf->nAllocatedLength + 1, sizeof(char)); /* djb-rwth: cast operator added */
     if (!stmp)
@@ -5458,7 +5672,7 @@ int MergeZzInHillFormula(INCHI_IOS_STRING *strbuf)
     inchi_strbuf_reset(strbuf);
     p0 = scopy;
     p = p0;
-    do 
+    do
     {
         /* djb-rwth: removing redundant code */
         pend = strchr(p, '.');
diff --git a/INCHI-1-SRC/INCHI_BASE/src/ichiprt2.c b/INCHI-1-SRC/INCHI_BASE/src/ichiprt2.c
index d9c37b6a..cef4b29c 100644
--- a/INCHI-1-SRC/INCHI_BASE/src/ichiprt2.c
+++ b/INCHI-1-SRC/INCHI_BASE/src/ichiprt2.c
@@ -471,8 +471,64 @@ int MakeMult( int mult,
     return 0;
 }
 
+/**
+ * @brief Adds the number to the string buffer.
+ *
+ * @param number Input number to be added
+ * @param szTailingDelim Pointer to the trailing delimiter string
+ * @param buf Pointer to the output string buffer
+ * @param nCtMode Mode flag for string representation
+ * @param bOverflow Pointer to overflow flag
+ * @return Returns the number of characters added to the buffer
+ */
+int MakeNumber_EnhStereo( int number,
+                          const char       *szTailingDelim,
+                          INCHI_IOS_STRING *buf,
+                          int              nCtMode,
+                          int              *bOverflow )
+{
+    char szValue[2048];
+    int  len = 0;
+    int len_delim;
+    int n;
+
+    if (*bOverflow)
+    {
+        return 0;
+    }
+    if (nCtMode & CT_MODE_ABC_NUMBERS)
+    {
+        len += MakeAbcNumber( szValue, ( int )sizeof( szValue ), NULL, number );
+    }
+    else
+    {
+        len += MakeDecNumber( szValue, ( int )sizeof( szValue ), NULL, number );
+    }
+    len_delim = (int) strlen( szTailingDelim );
+
+    if (len + len_delim < ( int )sizeof( szValue ))
+    {
+        strcpy(szValue + len, szTailingDelim);
+        n = inchi_strbuf_printf( buf, "%s", szValue );
+        if (-1 == n) *bOverflow |= 1;
+        return n;
+    }
+
+    *bOverflow |= 1;
+
+    return 0;
+}
+
 
 /****************************************************************************/
+/**
+ * @brief Adds the delimiter to the string buffer if it is not empty and there is no overflow.
+ *
+ * @param szTailingDelim Pointer to the trailing delimiter string
+ * @param buf Pointer to the output string buffer
+ * @param bOverflow Pointer to overflow flag
+ * @return Returns the number of characters added to the buffer, or 0 if the delimiter is empty or there is an overflow
+ */
 int MakeDelim( const char       *szTailingDelim,
                INCHI_IOS_STRING *buf,
                int              *bOverflow )
@@ -1464,7 +1520,7 @@ int MakeCRVString( ORIG_INFO        *OrigInfo,
                 }
                 /* radical */
                 if (OrigInfo[k].cRadical)
-                {                            
+                {
                     if (len >= 2047) /* djb-rwth: fixing coverity ID #499515 */
                     {
                         len = 2047;
@@ -2116,6 +2172,268 @@ int MakeStereoString( AT_NUMB          *at1,
     return nLen;
 }
 
+/**
+ * @brief Compares two integers for qsort.
+ *
+ * @param a First integer pointer.
+ * @param b Second integer pointer.
+ * @return Returns negative, zero, or positive value based on comparison.
+ */
+int compare_ints(const void *a, const void *b) {
+    int arg1 = *(const int *)a;
+    int arg2 = *(const int *)b;
+    return (arg1 > arg2) - (arg1 < arg2);
+}
+
+/**
+ * @brief Compares the third value of two integer arrays for qsort. Used to sort enhanced stereochemistry groups based on the canonical atom number of the first atom in the group.
+ *
+ * @param a First integer array pointer.
+ * @param b Second integer array pointer.
+ * @return Returns negative, zero, or positive value based on comparison.
+ */
+int compare_third_value(const void *a, const void *b) {
+    const int *arr1 = *(const int **)a;
+    const int *arr2 = *(const int **)b;
+    return arr1[2] - arr2[2];
+}
+
+/**
+ * @brief Creates the enhanced stereochemistry string for the s - layer.
+ *
+ * @param pAux Pointer to the INCHI_AUX structure.
+ * @param conf_stereo_string Pointer to the configuration stereochemistry string (abs, rel, rac).
+ * @param enh_stereo Pointer to list of enhanced stereochemistry groups.
+ * @param nof_stereo_groups Number of enhanced stereochemistry groups.
+ * @param strbuf Pointer to the output string buffer.
+ * @param nCtMode Mode flag for string representation.
+ * @param bOverflow Pointer to overflow flag.
+ * @return Returns the length of the created string.
+ */
+int MakeEnhStereoString( INChI_Aux        *pAux,
+                         INCHI_IOS_STRING *strbuf,
+                         const char*      conf_stereo_string,
+                         int              **enh_stereo,
+                         int              nof_stereo_groups,
+                         int              nCtMode,
+                         int              *bOverflow )
+{
+    int tot_len = 0;
+    int count_added = 0;
+
+    if (pAux == NULL) {
+        return 0;
+    }
+
+    if (enh_stereo == NULL) {
+        return 0;
+    }
+
+    if (nof_stereo_groups < 1) {
+        return 0;
+    }
+
+    tot_len += MakeDelim( conf_stereo_string, strbuf, bOverflow );
+
+    int **enh_stereo_canon = (int**)inchi_calloc(nof_stereo_groups, sizeof(int*));
+
+    // Converts the original atom numbers in the enhanced stereochemistry groups to canonical atom numbers
+    // and sorts the atoms within each group based on their canonical atom numbers. This ensures that the order of
+    // atoms in the string representation is consistent and does not depend on the order of atoms in the input data.
+    // enh_stereo_canon is a 2D array where each row corresponds to an enhanced stereochemistry group. The first element
+    // of each row (index 0) stores the number of atoms in the group, the second element (index 1) stores the count of found
+    // atoms, and the remaining elements (starting from index 2) store the canonical atom numbers of the atoms in the group.
+    for (int i = 0; i < nof_stereo_groups; i++) {
+        const int *atom_numbers = &enh_stereo[i][2];
+        int count_found_atoms = 0;
+        int nof_atoms = enh_stereo[i][1];
+
+        enh_stereo_canon[i] = (int*)inchi_calloc(nof_atoms + 2, sizeof(int));
+        enh_stereo_canon[i][0] = nof_atoms;
+        for (int j = 0; j < nof_atoms; j++)  {
+
+            int orig_atom_num = atom_numbers[j];
+            int canon_atom_num = get_canonical_atom_number(pAux, orig_atom_num);
+            if (canon_atom_num != -1) {
+                count_found_atoms++;
+            } else {
+                canon_atom_num = INT_MAX;
+            }
+
+            enh_stereo_canon[i][j + 2] = canon_atom_num;
+        }
+        enh_stereo_canon[i][1] = count_found_atoms;
+
+        if (nof_atoms > 1) {
+            qsort(&enh_stereo_canon[i][2], nof_atoms, sizeof(int), compare_ints);
+        }
+    }
+
+    // Sorts the enhanced stereochemistry groups based on the canonical atom number of the first atom in the group.
+    // This ensures that the groups are always in a consistent order in the string representation, regardless of the
+    // order they were added to the input data (e.g. AND1, AND2, ... or OR1, OR2, ...).
+    qsort(enh_stereo_canon, nof_stereo_groups, sizeof(int*), compare_third_value);
+
+    // Creates the string for the stereo group based on the canonical atom numbers of the atoms in the group. If no
+    // atoms were found for the group, it will not be added to the string.
+    for (int i = 0; i < nof_stereo_groups; i++) {
+        int nof_atoms = enh_stereo_canon[i][0];
+        int nof_found_atoms = enh_stereo_canon[i][1];
+
+        if (nof_found_atoms > 0) {
+            tot_len += MakeDelim( "(", strbuf, bOverflow );
+            for (int j = 0; j < nof_found_atoms; j++)  {
+                tot_len += MakeNumber_EnhStereo( enh_stereo_canon[i][j + 2], "", strbuf, nCtMode, bOverflow );
+                count_added++;
+
+                if ((j + 1) < nof_found_atoms) {
+                    tot_len += MakeDelim( ",", strbuf, bOverflow );
+                }
+            }
+            tot_len += MakeDelim( ")", strbuf, bOverflow );
+        }
+    }
+
+    for (int i = 0; i < nof_stereo_groups; i++) {
+        inchi_free(enh_stereo_canon[i]);
+    }
+    inchi_free(enh_stereo_canon);
+
+    // Removes the last value for the stereo group (1,2,3) if no atoms were added to the string
+    if (count_added == 0) {
+        if (strbuf && strbuf->nUsedLength > 0) {
+            strbuf->nUsedLength--;
+            strbuf->pStr[strbuf->nUsedLength] = '\0';
+        }
+
+        tot_len = tot_len - 1;
+    }
+
+    return tot_len;
+}
+
+/**
+ * @brief Creates the string for the s - layer based on the enhanced stereochemistry information.
+ *
+ * @param orig_inp_data Pointer to the original atom data.
+ * @param pINChISort Pointer to the INCHI_SORT structure.
+ * @param bOutType Output type flag.
+ * @param num_components Number of components in the molecule.
+ * @param strbuf Pointer to the output string buffer.
+ * @param nCtMode Mode flag for string representation.
+ * @param bOverflow Pointer to overflow flag.
+ * @return Returns the length of the created string.
+ */
+int MakeSlayerString( ORIG_ATOM_DATA   *orig_inp_data,
+                      INCHI_SORT       *pINChISort,
+                      INCHI_IOS_STRING *strbuf,
+                      int              bOutType,
+                      int              num_components,
+                      int              nCtMode,
+                      int              *bOverflow )
+{
+
+    int tot_len = 0;
+    int          ii;
+
+    const char* x_abs = "1";
+    const char* x_rel = "2";
+    const char* x_rac = "3";
+
+    const INCHI_SORT   *is = NULL;
+    const INCHI_SORT  *is0 = pINChISort;
+
+    // INChI        *pINChI = NULL;
+    INChI_Aux    *pAux = NULL;
+
+    char **dictionary = (char**)inchi_calloc(ENH_STEREO_DICT_SIZE, sizeof(char*));
+    int *counts = (int*)inchi_calloc(ENH_STEREO_DICT_SIZE, sizeof(int));
+
+    for (int i = 0; i < ENH_STEREO_DICT_SIZE; i++) {
+        dictionary[i] = NULL;
+        counts[i] = 0;
+    }
+
+    INCHI_IOS_STRING tmpbuf  = {0};
+
+    for (int cur_c = 0; !*bOverflow && cur_c < num_components; cur_c++)
+    {
+
+        is = is0 + cur_c;
+        // pINChI = ( 0 <= ( ii = GET_II( bOutType, is ) ) ) ? is->pINChI[ii] : NULL;
+        pAux = ( 0 <= ( ii = GET_II( bOutType, is ) ) ) ? is->pINChI_Aux[ii] : NULL;
+
+        inchi_strbuf_init(&tmpbuf, INCHI_STRBUF_INITIAL_SIZE, INCHI_STRBUF_SIZE_INCREMENT);
+
+        // s1
+        tot_len += MakeEnhStereoString( pAux,
+                                        &tmpbuf,
+                                        x_abs,
+                                        orig_inp_data->v3000->lists_steabs,
+                                        orig_inp_data->v3000->n_steabs,
+                                        nCtMode,
+                                        bOverflow);
+
+        // s2
+        tot_len += MakeEnhStereoString( pAux,
+                                        &tmpbuf,
+                                        x_rel,
+                                        orig_inp_data->v3000->lists_sterel,
+                                        orig_inp_data->v3000->n_sterel,
+                                        nCtMode,
+                                        bOverflow);
+
+        // s3
+        tot_len += MakeEnhStereoString( pAux,
+                                        &tmpbuf,
+                                        x_rac,
+                                        orig_inp_data->v3000->lists_sterac,
+                                        orig_inp_data->v3000->n_sterac,
+                                        nCtMode,
+                                        bOverflow);
+
+        int found = 0;
+        for (int i = 0; i < ENH_STEREO_DICT_SIZE; i++) {
+            if (dictionary[i] && strcmp(tmpbuf.pStr, dictionary[i]) == 0) {
+                counts[i]++;
+                found = 1;
+                break;
+            }
+        }
+        if (!found) {
+            for (int i = 0; i < ENH_STEREO_DICT_SIZE; i++) {
+                if (dictionary[i] == NULL) {
+                    dictionary[i] = strdup(tmpbuf.pStr);
+                    counts[i] = 1;
+                    break;
+                }
+            }
+        }
+        inchi_strbuf_close(&tmpbuf);
+    }
+
+    // String deduplication based on dictionary and counts
+    int count = 0;
+    for (int i = 0; i < ENH_STEREO_DICT_SIZE; i++) {
+        if (dictionary[i]) {
+            if (count > 0) {
+                tot_len += MakeDelim( ";", strbuf, bOverflow );
+            }
+            if (counts[i] > 1) {
+                tot_len = inchi_strbuf_printf(strbuf, "%d*%s", counts[i], dictionary[i]);
+            } else {
+                tot_len = inchi_strbuf_printf(strbuf, "%s", dictionary[i]);
+            }
+            inchi_free(dictionary[i]);
+            count++;
+        }
+    }
+
+    inchi_free(dictionary);
+    inchi_free(counts);
+
+    return tot_len;
+}
 
 #ifdef ALPHA_BASE
 #if ( ALPHA_BASE != 27 )
diff --git a/INCHI-1-SRC/INCHI_BASE/src/ichiprt3.c b/INCHI-1-SRC/INCHI_BASE/src/ichiprt3.c
index 6f51233f..a17b0324 100644
--- a/INCHI-1-SRC/INCHI_BASE/src/ichiprt3.c
+++ b/INCHI-1-SRC/INCHI_BASE/src/ichiprt3.c
@@ -718,10 +718,21 @@ int str_FixedH_atoms( INCHI_SORT       *pINChISort,
     return ( strbuf->nUsedLength - nUsedLength0 );
 }
 
-
-/****************************************************************************
-  Produce double bond stereo substring of the whole structure InChI string.
-****************************************************************************/
+/**
+ * @brief Produce double bond stereo substring of the whole structure InChI string.
+ *
+ * @param pINChISort Pointer to the primary INCHI_SORT structure containing input data.
+ * @param pINChISort2 Pointer to the secondary INCHI_SORT structure, used for comparison or additional data.
+ * @param strbuf Pointer to an INCHI_IOS_STRING buffer where the output string will be stored.
+ * @param bOverflow Pointer to an integer flag that will be set if the output overflows the buffer.
+ * @param bOutType Output type flag specifying the format or type of output.
+ * @param TAUT_MODE Tautomer mode flag indicating how tautomers are handled.
+ * @param num_components Number of components to process.
+ * @param bSecondNonTautPass Flag indicating if this is the second pass for non-tautomeric processing.
+ * @param bOmitRepetitions Flag to omit repeated entries in the output.
+ * @param bUseMulipliers Flag to use multipliers in the output representation.
+ * @return Returns number of characters written to strbuf
+ */
 int str_Sp2( INCHI_SORT       *pINChISort,
              INCHI_SORT       *pINChISort2,
              INCHI_IOS_STRING *strbuf,
@@ -950,10 +961,22 @@ int str_Sp2( INCHI_SORT       *pINChISort,
     return ( strbuf->nUsedLength - nUsedLength0 );
 }
 
-
-/****************************************************************************
-  Produce tetrahedral stereo substring of the whole structure InChI string.
-****************************************************************************/
+/**
+ * @brief Produce tetrahedral stereo substring of the whole structure InChI string.
+ *
+ * @param pINChISort Pointer to the primary INCHI_SORT structure containing input data.
+ * @param pINChISort2 Pointer to the secondary INCHI_SORT structure, used for comparison or additional data.
+ * @param strbuf Pointer to an INCHI_IOS_STRING buffer where the output string will be stored.
+ * @param bOverflow Pointer to an integer flag that will be set if the output overflows the buffer.
+ * @param bOutType Output type flag specifying the format or type of output.
+ * @param TAUT_MODE Tautomer mode flag indicating how tautomers are handled.
+ * @param num_components The number of components to process.
+ * @param bRelRac Flag for relative or racemic stereochemistry.
+ * @param bSecondNonTautPass Flag indicating if this is the second pass for non-tautomeric processing.
+ * @param bOmitRepetitions Flag to omit repeated entries in the output.
+ * @param bUseMulipliers Flag to use multipliers in the output representation.
+ * @return int
+ */
 int str_Sp3( INCHI_SORT       *pINChISort,
              INCHI_SORT       *pINChISort2,
              INCHI_IOS_STRING *strbuf,
@@ -1184,10 +1207,15 @@ int str_Sp3( INCHI_SORT       *pINChISort,
     return ( strbuf->nUsedLength - nUsedLength0 );
 }
 
-
-/****************************************************************************
-  Output abs stero inversion substring of the whole structure InChI string
-****************************************************************************/
+/**
+ * @brief Output absolute stereo inversion substring of the whole structure InChI string
+ * @param pINChISort Pointer to INCHI_SORT array
+ * @param strbuf Pointer to string buffer
+ * @param bOverflow Overflow flag
+ * @param bOutType Output type
+ * @param num_components Number of connected components
+ * @return Length of the added substring (return value '0', '1', or '.' in strbuf)
+ */
 int str_StereoAbsInv( INCHI_SORT       *pINChISort,
                       INCHI_IOS_STRING *strbuf,
                       int              *bOverflow,
@@ -4131,7 +4159,7 @@ int bin_AuxTautTrans( INCHI_SORT *pINChISort,
             if (nTrans_n && nTrans_s)
             {
                 /* new ordering number for original non-tautomeric component number is->ord_number */
-                nTrans_n[is->ord_number] = i + 1; /*nTrans_t[is2->ord_number] =*/ 
+                nTrans_n[is->ord_number] = i + 1; /*nTrans_t[is2->ord_number] =*/
             }
         }
     }
diff --git a/INCHI-1-SRC/INCHI_BASE/src/mode.h b/INCHI-1-SRC/INCHI_BASE/src/mode.h
index a83bbbc6..638b1c8c 100644
--- a/INCHI-1-SRC/INCHI_BASE/src/mode.h
+++ b/INCHI-1-SRC/INCHI_BASE/src/mode.h
@@ -376,7 +376,7 @@ extern "C" {
                                         /* InChI and sometimes resulted in memory corruption on     */
                                         /* accessing array of len == NUM_H_ISOTOPES that is 3.      */
 
-#define FIX_OLEAN_SPIRO_CHIRALITY_DETECTION_BUG 1 
+#define FIX_OLEAN_SPIRO_CHIRALITY_DETECTION_BUG 1
                                         /* (2018-05-03) thanks, DT; fix for 'olean spiro chirality' */
 
 
@@ -438,7 +438,7 @@ extern "C" {
 
 
 #define FIX_NP_MINUS_BUG  1         /* 2010-03-11 DT Fix for bug reported by Timo Boehme						*/
-                                    /* in normalization procedure for some structures containing N2(+) fragment	*/ 
+                                    /* in normalization procedure for some structures containing N2(+) fragment	*/
                                     /* which may result in producing different InChI strings for the same		*/
                                     /* molecule, depending on original order of the atomic numbers				*/
 
@@ -478,7 +478,7 @@ extern "C" {
 #define TAUT_PT_06_00              1 /* tautomerism rule PT_06_00 */
 #define TAUT_PT_39_00              1 /* tautomerism rule PT_39_00 */
 #define TAUT_PT_13_00              1 /* tautomerism rule PT_13_00 */
-#define TAUT_PT_18_00              1 /* tautomerism rule PT_18_00 */  
+#define TAUT_PT_18_00              1 /* tautomerism rule PT_18_00 */
 
 #ifdef  BUILD_WITH_ENG_OPTIONS
 #define UNDERIVATIZE               1 /* split to possible underivatized fragments */
@@ -634,6 +634,8 @@ extern "C" {
                                        /* 0=> allow other definitions (below) to be active */
 #define ONE_BAD_SB_NEIGHBOR         1  /* 1 => allow 1 "bad" bond type neighbor to a stereobond atom. 2004-06-02 */
 
+#define ENH_STEREO_DICT_SIZE        100 /* 100 => size of the dictionary for enhanced stereo */
+
 /* more stereo settings */
 #define BREAK_ONE_MORE_SC_TIE       1   /* break one more tie when comparing possible stereocenter neighbors */
 #define BREAK_ALSO_NEIGH_TIE        0   /* post 1.12Beta 2004-08-20: if fixed neighbor has equ neighbors, fix the one with smaller canon. rank */
@@ -1245,8 +1247,8 @@ do {\
 #define POLYMERS_MODERN 1	/* v. 1.06+ way to treat polymers with Zz			*/
 #define POLYMERS_LEGACY 2	/* v. 1.05 mode, no explicit Zz (internally they are here) */
 #define POLYMERS_LEGACY_PLUS 3	/* v. 1.05 mode with an addition of that in all
-                                   frame-shiftable-bistar-CRUs their backbone bonds 
-                                   are reordered in descending seniority order. 
+                                   frame-shiftable-bistar-CRUs their backbone bonds
+                                   are reordered in descending seniority order.
                                    Used as hidden 1st pass in 1.06 treatment		*/
 
 
diff --git a/INCHI-1-SRC/INCHI_BASE/src/mol2atom.c b/INCHI-1-SRC/INCHI_BASE/src/mol2atom.c
index 29e2389e..ed84245c 100644
--- a/INCHI-1-SRC/INCHI_BASE/src/mol2atom.c
+++ b/INCHI-1-SRC/INCHI_BASE/src/mol2atom.c
@@ -1337,6 +1337,7 @@ void FreeExtOrigAtData(OAD_Polymer *pd, OAD_V3000 *v3k)
 }
 
 /****************************************************************************/
+
 int SetExtOrigAtDataByMolfileExtInput(MOL_FMT_DATA *mfdata,
                                       OAD_Polymer **ppPolymer,
                                       OAD_V3000 **ppV3000,
diff --git a/INCHI-1-SRC/INCHI_BASE/src/mol_fmt3.c b/INCHI-1-SRC/INCHI_BASE/src/mol_fmt3.c
index ba9844ee..f2a4ffde 100644
--- a/INCHI-1-SRC/INCHI_BASE/src/mol_fmt3.c
+++ b/INCHI-1-SRC/INCHI_BASE/src/mol_fmt3.c
@@ -842,13 +842,13 @@ int MolfileV3000ReadCollections(MOL_FMT_CTAB *ctab,
         goto err_fin;
     }
 
-    /* Error: No V3000 Collection end marker */
-    if (ctab->v3000->n_steabs ||
-        ctab->v3000->n_sterel ||
-        ctab->v3000->n_sterac)
-    {
-        AddErrorMessage(pStrErr, "V3000 enhanced stereo read/stored but ignored");
-    }
+    // /* Error: No V3000 Collection end marker */
+    // if (ctab->v3000->n_steabs ||
+    //     ctab->v3000->n_sterel ||
+    //     ctab->v3000->n_sterac)
+    // {
+    //     AddErrorMessage(pStrErr, "V3000 enhanced stereo read/stored but ignored");
+    // }
 
 err_fin:
 
diff --git a/INCHI-1-SRC/INCHI_BASE/src/strutil.c b/INCHI-1-SRC/INCHI_BASE/src/strutil.c
index 981ff18a..cfaf9e8e 100644
--- a/INCHI-1-SRC/INCHI_BASE/src/strutil.c
+++ b/INCHI-1-SRC/INCHI_BASE/src/strutil.c
@@ -42,6 +42,7 @@
 #include <string.h>
 #include <ctype.h>
 #include <math.h>
+#include <limits.h>
 
 #include "mode.h"
 
@@ -1096,12 +1097,12 @@ int remove_ion_pairs( int num_atoms, inp_ATOM *at )
                         num_N_minus++;
                     }
 #ifdef FIX_P_IV_Plus_O_Minus
-                    num_P_IV_plus += a->el_number != EL_NUMBER_N && 
+                    num_P_IV_plus += a->el_number != EL_NUMBER_N &&
                                      chrg == 1 &&
-                                     a->valence == 4 && 
+                                     a->valence == 4 &&
                                      a->chem_bonds_valence == 4; /* added 2010-03-17 DT */
-#endif 
-                    break;                
+#endif
+                    break;
             }
         }
         else if (!chrg && a->chem_bonds_valence + NUMH( a, 0 ) == 2 &&
@@ -3674,7 +3675,7 @@ int move_explicit_Hcation( inp_ATOM *at,
 
         /* connect H to at[iat] */
         val = at[iat].valence;
-        
+
 #pragma warning (push)
 #pragma warning (disable: 6386)
         if (val < MAXVAL)
@@ -4269,6 +4270,195 @@ int cmp_components( const void *a1, const void *a2 )
     return ret;
 }
 
+/**
+ * @brief Get the canonical atom number from original atom number
+ *
+ * @param aux Pointer to INChI auxiliary data
+ * @param orig_atom_num Original atom number
+ * @return Returns the canonical atom number, or -1 if not found
+ */
+int get_canonical_atom_number( const INChI_Aux *aux,
+                               int orig_atom_num)
+{
+    if (aux == NULL) {
+        return -1;
+    }
+
+    if (aux->nOrigAtNosInCanonOrd == NULL) {
+        return -1;
+    }
+
+    for (int canon_num = 1; canon_num <= aux->nNumberOfAtoms; canon_num++) {
+        if (aux->nOrigAtNosInCanonOrd[canon_num - 1] == orig_atom_num) {
+            return canon_num;
+        }
+    }
+    return -1;
+}
+
+/**
+ * @brief Get the parity idx from canonical atom number object
+ *
+ * @param canon_atom_num Canonical atom number
+ * @param nNumber Pointer to array of canonical atom numbers
+ * @param nof_atoms Number of atoms
+ * @return Returns the parity index, or -1 if not found
+ */
+int get_parity_idx_from_canonical_atom_number( int canon_atom_num,
+                                               const AT_NUMB *nNumber,
+                                               int nof_atoms)
+{
+    if (nNumber == NULL) {
+        return -1;
+    }
+
+    if (nof_atoms <= 0) {
+        return -1;
+    }
+
+    for (int i = 0; i < nof_atoms; i++) {
+        if (nNumber[i] == canon_atom_num) {
+            return i;
+        }
+    }
+    return -1;
+}
+
+/**
+ * @brief Invert the parities for enhanced stereochemistry t- and m-layers
+ *
+ * @param inchi Pointer to INChI structure
+ * @param aux Pointer to INChI auxiliary data
+ * @param list_atoms Pointer to list of atom lists for abs, rel or rac information
+ * @param nof_lists Number of lists
+ * @param is_absolute Flag indicating if processing absolute stereochemistry
+ * @return Returns 0 on success, 1 if list_atoms is NULL
+ */
+int invert_parities(const INChI *inchi,
+                    const INChI_Aux *aux,
+                    int **list_atoms,
+                    int nof_lists,
+                    int is_absolute)
+{
+
+    // t - layer: parities
+    // 2 = +
+    // 1 = -
+
+    // m - layer
+    // -1 = m0
+    //  1 = m1
+
+    if (list_atoms == NULL) {
+        return 1;
+    }
+
+    if (nof_lists == 0)
+    {
+        return 1;
+    }
+
+    S_CHAR *t_parity = inchi->Stereo->t_parity;
+
+    for (int i = 0; i < nof_lists; i++) {
+        int nof_atoms = list_atoms[i][1];
+
+        AT_NUMB min_c_atom_num = (AT_NUMB)INT_MAX;
+        for (int j = 0; j < nof_atoms; j++) {
+            int orig_atom_num = list_atoms[i][2 + j];
+            AT_NUMB canon_atom_num = (AT_NUMB)get_canonical_atom_number(aux, orig_atom_num);
+            if (canon_atom_num < min_c_atom_num) {
+                min_c_atom_num = canon_atom_num;
+            }
+        }
+        if (min_c_atom_num == (AT_NUMB)INT_MAX) {
+            continue;
+        }
+        int min_c_parity_idx = get_parity_idx_from_canonical_atom_number(min_c_atom_num,
+                                                                         inchi->Stereo->nNumber,
+                                                                         inchi->Stereo->nNumberOfStereoCenters);
+
+        if (min_c_parity_idx == -1) {
+            continue;
+        }
+
+        int min_c_atom_parity = t_parity[min_c_parity_idx];
+        if (min_c_atom_parity == 2) {
+
+            for (int j = 0; j < nof_atoms; j++) {
+                int orig_atom_num = list_atoms[i][2 + j];
+                AT_NUMB canon_atom_num = (AT_NUMB)get_canonical_atom_number(aux, orig_atom_num);
+                int parity_idx = get_parity_idx_from_canonical_atom_number(canon_atom_num,
+                                                                            inchi->Stereo->nNumber,
+                                                                            inchi->Stereo->nNumberOfStereoCenters);
+
+                if (parity_idx == -1) {
+                    continue;
+                }
+
+                if (t_parity[parity_idx] == 2) {
+                    t_parity[parity_idx] = 1;
+                } else if(t_parity[parity_idx] == 1) {
+                    t_parity[parity_idx] = 2;
+                }
+            }
+
+            if (is_absolute) {
+                inchi->Stereo->nCompInv2Abs = -1; //m1
+            }
+        }
+    }
+    return 0;
+}
+
+/**
+ * @brief Set the enhanced stereochemistry information for t- and m-layers
+ *
+ * @param orig_inp_data Pointer to original input atom data
+ * @param inchi Pointer to INChI structure
+ * @param aux Pointer to INChI auxiliary data
+ * @return Retruns 1 if not V3000, otherwise 0
+ */
+int set_EnhancedStereo_t_m_layers( const ORIG_ATOM_DATA *orig_inp_data,
+                                   const INChI *inchi,
+                                   const INChI_Aux *aux)
+{
+    int ret = 0;
+
+    if (!orig_inp_data->v3000)
+    {
+        return 1;
+    }
+
+    if (inchi == NULL || aux == NULL)
+    {
+        return 1;
+    }
+
+    if (inchi->Stereo == NULL ||
+        inchi->Stereo->t_parity == NULL ||
+        inchi->Stereo->nNumber == NULL ||
+        inchi->Stereo->nNumberOfStereoCenters <= 0) {
+        return 1;
+    }
+
+    if (aux->nOrigAtNosInCanonOrd == NULL ||
+        aux->nNumberOfAtoms <= 0) {
+        return 1;
+    }
+
+    int ret_abs = invert_parities(inchi, aux, orig_inp_data->v3000->lists_steabs, orig_inp_data->v3000->n_steabs, 1);
+    int ret_rac = invert_parities(inchi, aux, orig_inp_data->v3000->lists_sterac, orig_inp_data->v3000->n_sterac, 0);
+    int ret_rel = invert_parities(inchi, aux, orig_inp_data->v3000->lists_sterel, orig_inp_data->v3000->n_sterel, 0);
+
+    if ((orig_inp_data->v3000->n_steabs == 0) &&
+        (orig_inp_data->v3000->n_sterel > 0 ||
+         orig_inp_data->v3000->n_sterac)) {
+        inchi->Stereo->nCompInv2Abs = 1; //m0
+    }
+
+    return ret;
+}
 
 /****************************************************************************
 Set the (disconnected) component numbers in ORIG_ATOM_DATA 'at[*].component'
@@ -4324,7 +4514,7 @@ int MarkDisconnectedComponents( ORIG_ATOM_DATA *orig_at_data,
     nPrevAtom = (AT_NUMB*)inchi_calloc(num_at, sizeof(nPrevAtom[0]));
     iNeigh = (S_CHAR*)inchi_calloc(num_at, sizeof(iNeigh[0]));
 
-    if (!nNewCompNumber || !nPrevAtom || !iNeigh) /* nNewCompNumber: for non-recursive DFS only: */ 
+    if (!nNewCompNumber || !nPrevAtom || !iNeigh) /* nNewCompNumber: for non-recursive DFS only: */
     {
         goto exit_function;
     }
@@ -4333,7 +4523,7 @@ int MarkDisconnectedComponents( ORIG_ATOM_DATA *orig_at_data,
 
     /* Mark and count; avoid deep DFS recursion: it may make verifying software unhappy */
     /* nNewCompNumber[i] will contain new component number for atoms at[i], i=0..num_at-1 */
-    
+
     for (j = 0; j < num_at; j++)
     {
         if (!nNewCompNumber[j])
@@ -4709,7 +4899,7 @@ int Free_INChI_Members( INChI *pINChI )
         qzfree(pINChI->IsotopicAtom);
         qzfree(pINChI->IsotopicTGroup);
         qzfree(pINChI->nPossibleLocationsOfIsotopicH);
-        qzfree( pINChI->Stereo );       
+        qzfree( pINChI->Stereo );
         qzfree( pINChI->StereoIsotopic );
         qzfree( pINChI->szHillFormula );
     }
@@ -5004,7 +5194,7 @@ void CompAtomData_GetNumMapping( COMP_ATOM_DATA *adata, int *orig_num, int *curr
 ****************************************************************************/
 int imat_new( int m, int n, int ***a )
 {
-    int i;   
+    int i;
     if (m == 0 || n == 0)
     {
         return 0;
@@ -5106,7 +5296,7 @@ subgraf *subgraf_new( ORIG_ATOM_DATA *orig_inp_data,
         sg->orig2node[sg->nodes[i]] = i;
     }
 
-    /* Create and fill subgraph adjacency matrix based on nodes/orig atom numbers 
+    /* Create and fill subgraph adjacency matrix based on nodes/orig atom numbers
        and connections stored in orig_inp_data */
     sg->adj = (subgraf_edge **) inchi_calloc( nnodes, sizeof( subgraf_edge * ) );
     if (!sg->adj)
@@ -5266,7 +5456,7 @@ void subgraf_pathfinder_free( subgraf_pathfinder *spf )
 
 
 /****************************************************************************
- Find path(s) from subgraf node spf->start to spf->end 
+ Find path(s) from subgraf node spf->start to spf->end
  and fill bonds[nbonds] and atoms[natoms]
  Do not traverse through supplied forbidden edges (if not zero/NULL)
 ****************************************************************************/
@@ -5298,7 +5488,7 @@ void subgraf_pathfinder_run( subgraf_pathfinder *spf,
             continue;
         }
         if (nforbidden && forbidden)
-        {	
+        {
             skip = 0;
             for (f = 0; f < nforbidden; f++)
             {
diff --git a/INCHI-1-SRC/INCHI_BASE/src/strutil.h b/INCHI-1-SRC/INCHI_BASE/src/strutil.h
index 14af75ba..df950476 100644
--- a/INCHI-1-SRC/INCHI_BASE/src/strutil.h
+++ b/INCHI-1-SRC/INCHI_BASE/src/strutil.h
@@ -57,6 +57,57 @@ extern "C"
     struct tagTautomerGroupsInfo;
     struct tagCANON_GLOBALS;
 
+    /**
+     * @brief Set the enhanced stereochemistry for t- and m-layers
+     *
+     * @param orig_inp_data
+     * @param inchi
+     * @param aux
+     * @return int
+     */
+    int set_EnhancedStereo_t_m_layers(const ORIG_ATOM_DATA *orig_inp_data,
+                                      const INChI *inchi,
+                                      const INChI_Aux *aux);
+
+    /**
+     * @brief Get the canonical atom number object
+     *
+     * @param aux Pointer to INChI_Aux data structure
+     * @param orig_atom_num Original atom number
+     * @return Returns canonical atom number if found, -1 if not
+     */
+    int get_canonical_atom_number( const INChI_Aux *aux,
+                                   int orig_atom_num);
+
+    /**
+     * @brief Get the parity index from canonical atom number
+     *
+     * @param canon_atom_num Canonical atom number
+     * @param nNumber Pointer to atom number array
+     * @param nof_atoms Number of atoms
+     * @return Returns parity index if found, -1 if not
+     */
+    int get_parity_idx_from_canonical_atom_number( int canon_atom_num,
+                                                   const AT_NUMB *nNumber,
+                                                   int nof_atoms);
+
+    /**
+     * @brief Invert the parities for enhanced stereochemistry t- and m-layers
+     *
+     * @param inchi Pointer to INChI structure
+     * @param aux Pointer to INChI auxiliary data
+     * @param list_atoms Pointer to list of atom lists for abs, rel or rac information
+     * @param nof_lists Number of lists
+     * @param is_absolute Flag indicating if processing absolute stereochemistry
+     * @return Returns 0 on success, 1 if list_atoms is NULL
+     */
+
+    int invert_parities(const INChI *inchi,
+                        const INChI_Aux *aux,
+                        int **list_atoms,
+                        int nof_lists,
+                        int is_absolute);
+
     /**
      * @brief Extract one (connected) component
      *
@@ -407,9 +458,9 @@ extern "C"
      * @brief Compares stereo information of two structures
      *
      * @param s1 Pointer to stereo information of first structure
-     * @param eql1 Flag for stereo information check
+     * @param eql1 Flag for stereo information check (EQL_EXISTS, EQL_SP3, EQL_SP3_INV, EQL_SP2)
      * @param s2 Pointer to stereo information of second structure
-     * @param eql2 Flag for stereo information check
+     * @param eql2 Flag for stereo information check (EQL_EXISTS, EQL_SP3, EQL_SP3_INV, EQL_SP2)
      * @param bRelRac Flag to compare racemic stereo information
      * @return int 0 if unequal, 1 if equal
      */
diff --git a/INCHI-1-SRC/INCHI_BASE/src/util.c b/INCHI-1-SRC/INCHI_BASE/src/util.c
index 72a518bb..e72f89e8 100644
--- a/INCHI-1-SRC/INCHI_BASE/src/util.c
+++ b/INCHI-1-SRC/INCHI_BASE/src/util.c
@@ -263,10 +263,10 @@ const ELDATA ElData[] =
 { "Zy",   0,   0,   0.000000000,     0 ,  0,  1, {{0,},       {0,},       {1,},       {0,},       {0,}       }},
 { "Zz",   0,   0,   0.000000000,     0 ,  0,  1, {{0,},       {0,},       {1,},       {0,},       {0,}       }},
 #ifdef INCHI_ZFRAG
-{ "Zu",   0,   0,   0.000000000,     0 ,  0,  1, {{0,},       {0,},       {1,},       {0,},       {0,}       }}, 
-{ "Zv",   0,   0,   0.000000000,     0 ,  0,  1, {{0,},       {0,},       {2,},       {0,},       {0,}       }}, 
-{ "Zw",   0,   0,   0.000000000,     0 ,  0,  1, {{0,},       {0,},       {3,},       {0,},       {0,}       }}, 
-{ "Zx",   0,   0,   0.000000000,     0 ,  0,  1, {{0,},       {0,},       {1,2,},     {0,},       {0,}       }}, 
+{ "Zu",   0,   0,   0.000000000,     0 ,  0,  1, {{0,},       {0,},       {1,},       {0,},       {0,}       }},
+{ "Zv",   0,   0,   0.000000000,     0 ,  0,  1, {{0,},       {0,},       {2,},       {0,},       {0,}       }},
+{ "Zw",   0,   0,   0.000000000,     0 ,  0,  1, {{0,},       {0,},       {3,},       {0,},       {0,}       }},
+{ "Zx",   0,   0,   0.000000000,     0 ,  0,  1, {{0,},       {0,},       {1,2,},     {0,},       {0,}       }},
 #endif
 
 { "",     0,   0,   0.000000000,     0 ,  0,  0, {{0,},       {0,},       {0,},       {0,},       {0,}       }},
@@ -376,36 +376,36 @@ int get_periodic_table_number( const char* elname )
     }
 
     /* the single letter (common) elements */
-    if (!elname[1]) 
+    if (!elname[1])
     {
-        switch (elname[0]) 
+        switch (elname[0])
         {
-            case 'H': 
-                return EL_NUMBER_H; 
+            case 'H':
+                return EL_NUMBER_H;
                 break;
-            case 'B': 
-                return EL_NUMBER_B; 
+            case 'B':
+                return EL_NUMBER_B;
                 break;
-            case 'C': 
-                return EL_NUMBER_C; 
+            case 'C':
+                return EL_NUMBER_C;
                 break;
-            case 'N': 
-                return EL_NUMBER_N; 
+            case 'N':
+                return EL_NUMBER_N;
                 break;
-            case 'O': 
-                return EL_NUMBER_O; 
+            case 'O':
+                return EL_NUMBER_O;
                 break;
-            case 'P': 
-                return EL_NUMBER_P; 
+            case 'P':
+                return EL_NUMBER_P;
                 break;
-            case 'S': 
-                return EL_NUMBER_S; 
+            case 'S':
+                return EL_NUMBER_S;
                 break;
-            case 'F': 
-                return EL_NUMBER_F; 
+            case 'F':
+                return EL_NUMBER_F;
                 break;
-            case 'I': 
-                return EL_NUMBER_I; 
+            case 'I':
+                return EL_NUMBER_I;
                 break;
         }
     }
@@ -1065,7 +1065,6 @@ AT_NUMB *is_in_the_list( AT_NUMB *pathAtom, AT_NUMB nNextAtom, int nPathLen )
     return nPathLen ? pathAtom : NULL;
 }
 
-
 /****************************************************************************
   Check if integer is in the list
 ****************************************************************************/
@@ -1150,12 +1149,12 @@ int num_of_H( inp_ATOM *at, int iat )
 /****************************************************************************/
 U_CHAR ion_el_group( int el )
 {
-    switch ( el ) 
+    switch ( el )
     {
         case EL_NUMBER_C: /* fallthrough */
-#if ( FIX_REM_ION_PAIRS_Si_BUG == 1 )        
+#if ( FIX_REM_ION_PAIRS_Si_BUG == 1 )
         case EL_NUMBER_SI:
-#endif        
+#endif
             return EL_NUMBER_C;
         case EL_NUMBER_N: /* fallthrough */
         case EL_NUMBER_P:
@@ -1507,17 +1506,17 @@ int MakeRemovedProtonsString( int nNumRemovedProtons,
 
 /****************************************************************************/
 int get_endpoint_valence( U_CHAR el_number )
-{   
-    switch (el_number) 
+{
+    switch (el_number)
     {
         case EL_NUMBER_O:  /* fallthrough */
-        case EL_NUMBER_S:  
-        case EL_NUMBER_SE: 
-        case EL_NUMBER_TE: 
+        case EL_NUMBER_S:
+        case EL_NUMBER_SE:
+        case EL_NUMBER_TE:
             return 2;
-        case EL_NUMBER_N:  
+        case EL_NUMBER_N:
             return 3;
-        default: 
+        default:
             return 0;
     }
 }
@@ -1529,13 +1528,13 @@ int get_endpoint_valence( U_CHAR el_number )
 /****************************************************************************/
 int get_endpoint_valence_KET( U_CHAR el_number )
 {
-    switch (el_number) 
+    switch (el_number)
     {
-        case EL_NUMBER_C: 
+        case EL_NUMBER_C:
             return 4;
-        case EL_NUMBER_O: 
+        case EL_NUMBER_O:
             return 2;
-        default: 
+        default:
             return 0;
     }
 }
@@ -1768,7 +1767,7 @@ int mystrncpy( char *target, const char *source, unsigned maxlen )
     }
 
     /* giallu: PR #163 */
-    /* Find actual source length first to limit memchr search */ 
+    /* Find actual source length first to limit memchr search */
     source_len = (unsigned)strlen(source);
 
     if (source_len < maxlen)
@@ -1777,12 +1776,12 @@ int mystrncpy( char *target, const char *source, unsigned maxlen )
         len = source_len;
     }
     else if ((p = (const char*)memchr(source, 0, maxlen))) /* djb-rwth: addressing LLVM warning */
-    {    
+    {
         /* maxlen does not include the found zero termination */
         len = (int) ( p - source );
     }
     else
-    {    
+    {
         /*  reduced length does not include one more byte for zero termination */
         len = maxlen - 1;
     }
@@ -1816,7 +1815,7 @@ char* lrtrim( char *p, int* nLen )
             len -= i; /* djb-rwth: variable has to be decreased before memmove */
             (memmove)(p, p + i, ((long long)len + 1)); /* djb-rwth: now cast operator can be added */
         }
-            
+
         for (; 0 < len && is_ascii( p[len - 1] ) && isspace( p[len - 1] ); len--)
         {
             ;
diff --git a/INCHI-1-TEST/tests/test_executable/test_io.py b/INCHI-1-TEST/tests/test_executable/test_io.py
index d507960f..dd38d1ed 100644
--- a/INCHI-1-TEST/tests/test_executable/test_io.py
+++ b/INCHI-1-TEST/tests/test_executable/test_io.py
@@ -59,7 +59,8 @@ def test_executable_rejects_more_than_999_atoms(
     result = run_inchi_exe(molfile_v3000_more_than_999_atoms_and_bonds)
 
     assert (
-        "Error 170 (no InChI; V3000 enhanced stereo read/stored but ignored; Too many atoms [did you forget 'LargeMolecules' switch?])"
+        # "Error 170 (no InChI; V3000 enhanced stereo read/stored but ignored; Too many atoms [did you forget 'LargeMolecules' switch?])"
+        "Error 170 (no InChI; Too many atoms [did you forget 'LargeMolecules' switch?])"
         in result.stderr
     )
 
@@ -72,7 +73,8 @@ def test_executable_accepts_more_than_999_atoms_with_flag(
     )
 
     assert (
-        "Error 170 (no InChI; V3000 enhanced stereo read/stored but ignored; Too many atoms [did you forget 'LargeMolecules' switch?])"
+        # "Error 170 (no InChI; V3000 enhanced stereo read/stored but ignored; Too many atoms [did you forget 'LargeMolecules' switch?])"
+        "Error 170 (no InChI; Too many atoms [did you forget 'LargeMolecules' switch?])"
         not in result.stderr
     )
     assert "Experimental mode: Up to 32766 atoms per structure" in result.stderr
diff --git a/INCHI-1-TEST/tests/test_unit/CMakeLists.txt b/INCHI-1-TEST/tests/test_unit/CMakeLists.txt
index 248af435..0419209c 100644
--- a/INCHI-1-TEST/tests/test_unit/CMakeLists.txt
+++ b/INCHI-1-TEST/tests/test_unit/CMakeLists.txt
@@ -13,6 +13,12 @@ file(GLOB TEST_SOURCES CONFIGURE_DEPENDS "${CMAKE_CURRENT_SOURCE_DIR}/test_*.cpp
 foreach(test_src ${TEST_SOURCES})
     get_filename_component(test_name "${test_src}" NAME_WE)
     add_executable(${test_name} ${test_src})
+    target_compile_options(${test_name} PRIVATE
+        "$<$<CONFIG:Debug>:-g;-O0;-fsanitize=address>"
+    )
+    target_link_options(${test_name} PRIVATE
+        "$<$<CONFIG:Debug>:-g;-O0;-fsanitize=address>"
+    )
     target_link_libraries(${test_name} PRIVATE gtest_main gmock_main test_dependencies libinchi)
     add_test(NAME ${test_name} COMMAND $<TARGET_FILE:${test_name}>)
 endforeach()
diff --git a/INCHI-1-TEST/tests/test_unit/fixtures/enh_stereo_test_file_1.sdf b/INCHI-1-TEST/tests/test_unit/fixtures/enh_stereo_test_file_1.sdf
new file mode 100644
index 00000000..1bffa89f
--- /dev/null
+++ b/INCHI-1-TEST/tests/test_unit/fixtures/enh_stereo_test_file_1.sdf
@@ -0,0 +1,1016 @@
+Structure drawings enhanced stereochemistry.sdf
+  ChemDraw01282608392D
+
+  0  0  0     0  0              0 V3000
+M  V30 BEGIN CTAB
+M  V30 COUNTS 7 6 0 0 1
+M  V30 BEGIN ATOM
+M  V30 1 C -1.429260 -0.206189 0.000000 0
+M  V30 2 C -0.714790 0.206311 0.000000 0
+M  V30 3 O -0.714790 1.031557 0.000000 0
+M  V30 4 C -0.000107 -0.206312 0.000000 0
+M  V30 5 C 0.714577 0.206311 0.000000 0
+M  V30 6 C 1.429260 -0.206312 0.000000 0
+M  V30 7 N -0.000107 -1.031557 0.000000 0
+M  V30 END ATOM
+M  V30 BEGIN BOND
+M  V30 1 1 1 2
+M  V30 2 1 2 3 CFG=1
+M  V30 3 1 2 4
+M  V30 4 1 4 5
+M  V30 5 1 5 6
+M  V30 6 1 4 7 CFG=1
+M  V30 END BOND
+M  V30 END CTAB
+M  END
+$$$$
+Structure drawings enhanced stereochemistry.sdf
+  ChemDraw01282608392D
+
+  0  0  0     0  0              0 V3000
+M  V30 BEGIN CTAB
+M  V30 COUNTS 5 4 0 0 0
+M  V30 BEGIN ATOM
+M  V30 1 C 1.071918 -0.206311 0.000000 0
+M  V30 2 C 0.357235 -0.618934 0.000000 0
+M  V30 3 C -0.357448 -0.206311 0.000000 0
+M  V30 4 O -0.357448 0.618934 0.000000 0
+M  V30 5 C -1.071918 -0.618811 0.000000 0
+M  V30 END ATOM
+M  V30 BEGIN BOND
+M  V30 1 1 2 1
+M  V30 2 1 3 2
+M  V30 3 1 3 4 CFG=1
+M  V30 4 1 5 3
+M  V30 END BOND
+M  V30 BEGIN COLLECTION
+M  V30 MDLV30/STEREL1 ATOMS=(1 3)
+M  V30 END COLLECTION
+M  V30 END CTAB
+M  END
+$$$$
+Structure drawings enhanced stereochemistry.sdf
+  ChemDraw01282608392D
+
+  0  0  0     0  0              0 V3000
+M  V30 BEGIN CTAB
+M  V30 COUNTS 7 6 0 0 0
+M  V30 BEGIN ATOM
+M  V30 1 C 1.429260 -0.206311 0.000000 0
+M  V30 2 C 0.714576 0.206311 0.000000 0
+M  V30 3 C -0.000107 -0.206311 0.000000 0
+M  V30 4 N -0.000107 -1.031556 0.000000 0
+M  V30 5 C -0.714790 0.206311 0.000000 0
+M  V30 6 O -0.714790 1.031556 0.000000 0
+M  V30 7 C -1.429260 -0.206189 0.000000 0
+M  V30 END ATOM
+M  V30 BEGIN BOND
+M  V30 1 1 2 1
+M  V30 2 1 3 2
+M  V30 3 1 3 4 CFG=1
+M  V30 4 1 5 3
+M  V30 5 1 5 6 CFG=1
+M  V30 6 1 7 5
+M  V30 END BOND
+M  V30 BEGIN COLLECTION
+M  V30 MDLV30/STEREL1 ATOMS=(2 3 5)
+M  V30 END COLLECTION
+M  V30 END CTAB
+M  END
+$$$$
+Structure drawings enhanced stereochemistry.sdf
+  ChemDraw01282608392D
+
+  0  0  0     0  0              0 V3000
+M  V30 BEGIN CTAB
+M  V30 COUNTS 5 4 0 0 1
+M  V30 BEGIN ATOM
+M  V30 1 C 1.071919 -0.206311 0.000000 0
+M  V30 2 C 0.357235 -0.618934 0.000000 0
+M  V30 3 C -0.357448 -0.206311 0.000000 0
+M  V30 4 O -0.357448 0.618934 0.000000 0
+M  V30 5 C -1.071919 -0.618811 0.000000 0
+M  V30 END ATOM
+M  V30 BEGIN BOND
+M  V30 1 1 2 1
+M  V30 2 1 3 2
+M  V30 3 1 3 4 CFG=1
+M  V30 4 1 5 3
+M  V30 END BOND
+M  V30 END CTAB
+M  END
+$$$$
+Structure drawings enhanced stereochemistry.sdf
+  ChemDraw01282608392D
+
+  0  0  0     0  0              0 V3000
+M  V30 BEGIN CTAB
+M  V30 COUNTS 7 6 0 0 0
+M  V30 BEGIN ATOM
+M  V30 1 C 1.429261 -0.206311 0.000000 0
+M  V30 2 C 0.714577 0.206311 0.000000 0
+M  V30 3 C -0.000106 -0.206311 0.000000 0
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+M  V30 6 O -0.714790 1.031556 0.000000 0
+M  V30 7 C -1.429261 -0.206189 0.000000 0
+M  V30 END ATOM
+M  V30 BEGIN BOND
+M  V30 1 1 2 1
+M  V30 2 1 3 2
+M  V30 3 1 3 4 CFG=1
+M  V30 4 1 5 3
+M  V30 5 1 5 6 CFG=1
+M  V30 6 1 7 5
+M  V30 END BOND
+M  V30 BEGIN COLLECTION
+M  V30 MDLV30/STEREL2 ATOMS=(1 3)
+M  V30 MDLV30/STEREL1 ATOMS=(1 5)
+M  V30 END COLLECTION
+M  V30 END CTAB
+M  END
+$$$$
+Structure drawings enhanced stereochemistry.sdf
+  ChemDraw01282608392D
+
+  0  0  0     0  0              0 V3000
+M  V30 BEGIN CTAB
+M  V30 COUNTS 7 6 0 0 0
+M  V30 BEGIN ATOM
+M  V30 1 C 1.429261 -0.206311 0.000000 0
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+M  V30 1 1 2 1
+M  V30 2 1 3 2
+M  V30 3 1 3 4
+M  V30 4 1 5 3
+M  V30 5 1 5 6
+M  V30 6 1 7 5
+M  V30 END BOND
+M  V30 END CTAB
+M  END
+$$$$
+Structure drawings enhanced stereochemistry.sdf
+  ChemDraw01282608392D
+
+  0  0  0     0  0              0 V3000
+M  V30 BEGIN CTAB
+M  V30 COUNTS 7 6 0 0 0
+M  V30 BEGIN ATOM
+M  V30 1 N -0.000106 -1.031556 0.000000 0
+M  V30 2 C -0.000106 -0.206311 0.000000 0
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+M  V30 1 1 2 1 CFG=1
+M  V30 2 1 2 3
+M  V30 3 1 3 4
+M  V30 4 1 5 2
+M  V30 5 1 5 6 CFG=1
+M  V30 6 1 7 5
+M  V30 END BOND
+M  V30 BEGIN COLLECTION
+M  V30 MDLV30/STERAC1 ATOMS=(2 2 5)
+M  V30 END COLLECTION
+M  V30 END CTAB
+M  END
+$$$$
+Structure drawings enhanced stereochemistry.sdf
+  ChemDraw01282608392D
+
+  0  0  0     0  0              0 V3000
+M  V30 BEGIN CTAB
+M  V30 COUNTS 5 4 0 0 0
+M  V30 BEGIN ATOM
+M  V30 1 C 1.071919 -0.206311 0.000000 0
+M  V30 2 C 0.357236 -0.618934 0.000000 0
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+M  V30 4 O -0.357448 0.618934 0.000000 0
+M  V30 5 C -1.071919 -0.618811 0.000000 0
+M  V30 END ATOM
+M  V30 BEGIN BOND
+M  V30 1 1 2 1
+M  V30 2 1 3 2
+M  V30 3 1 3 4 CFG=1
+M  V30 4 1 5 3
+M  V30 END BOND
+M  V30 BEGIN COLLECTION
+M  V30 MDLV30/STERAC1 ATOMS=(1 3)
+M  V30 END COLLECTION
+M  V30 END CTAB
+M  END
+$$$$
+Structure drawings enhanced stereochemistry.sdf
+  ChemDraw01282608392D
+
+  0  0  0     0  0              0 V3000
+M  V30 BEGIN CTAB
+M  V30 COUNTS 5 4 0 0 0
+M  V30 BEGIN ATOM
+M  V30 1 C 1.071919 -0.206311 0.000000 0
+M  V30 2 C 0.357236 -0.618934 0.000000 0
+M  V30 3 C -0.357448 -0.206311 0.000000 0
+M  V30 4 O -0.357448 0.618934 0.000000 0
+M  V30 5 C -1.071919 -0.618811 0.000000 0
+M  V30 END ATOM
+M  V30 BEGIN BOND
+M  V30 1 1 2 1
+M  V30 2 1 3 2
+M  V30 3 1 3 4
+M  V30 4 1 5 3
+M  V30 END BOND
+M  V30 END CTAB
+M  END
+$$$$
+Structure drawings enhanced stereochemistry.sdf
+  ChemDraw01282608392D
+
+  0  0  0     0  0              0 V3000
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+M  V30 COUNTS 7 6 0 0 0
+M  V30 BEGIN ATOM
+M  V30 1 N -0.000106 -1.031556 0.000000 0
+M  V30 2 C -0.000106 -0.206311 0.000000 0
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+M  V30 4 C 1.429261 -0.206311 0.000000 0
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+M  V30 6 O -0.714789 1.031556 0.000000 0
+M  V30 7 C -1.429261 -0.206189 0.000000 0
+M  V30 END ATOM
+M  V30 BEGIN BOND
+M  V30 1 1 2 1 CFG=1
+M  V30 2 1 2 3
+M  V30 3 1 3 4
+M  V30 4 1 5 2
+M  V30 5 1 5 6 CFG=1
+M  V30 6 1 7 5
+M  V30 END BOND
+M  V30 BEGIN COLLECTION
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+M  V30 9 C -1.786602 -0.206188 0.000000 0
+M  V30 END ATOM
+M  V30 BEGIN BOND
+M  V30 1 1 2 1
+M  V30 2 1 3 2
+M  V30 3 1 3 4 CFG=1
+M  V30 4 1 5 3
+M  V30 5 1 5 6 CFG=1
+M  V30 6 1 7 5
+M  V30 7 1 7 8 CFG=1
+M  V30 8 1 9 7
+M  V30 END BOND
+M  V30 BEGIN COLLECTION
+M  V30 MDLV30/STERAC1 ATOMS=(2 3 5)
+M  V30 MDLV30/STEABS ATOMS=(1 7)
+M  V30 END COLLECTION
+M  V30 END CTAB
+M  END
+$$$$
+Structure drawings enhanced stereochemistry.sdf
+  ChemDraw01282608392D
+
+  0  0  0     0  0              0 V3000
+M  V30 BEGIN CTAB
+M  V30 COUNTS 9 9 0 0 0
+M  V30 BEGIN ATOM
+M  V30 1 O 0.824839 -1.071585 0.000000 0
+M  V30 2 C 0.412473 -0.357346 0.000000 0
+M  V30 3 C -0.412509 -0.357346 0.000000 0
+M  V30 4 C -0.824981 0.357119 0.000000 0
+M  V30 5 O -1.649713 0.357119 0.000000 0
+M  V30 6 C -0.412472 1.071585 0.000000 0
+M  V30 7 C 0.412510 1.071585 0.000000 0
+M  V30 8 C 0.824982 0.357119 0.000000 0
+M  V30 9 O 1.649713 0.357119 0.000000 0
+M  V30 END ATOM
+M  V30 BEGIN BOND
+M  V30 1 1 2 1 CFG=1
+M  V30 2 1 3 2
+M  V30 3 1 4 3
+M  V30 4 1 4 5 CFG=1
+M  V30 5 1 6 4
+M  V30 6 1 6 7
+M  V30 7 1 8 7
+M  V30 8 1 8 9 CFG=1
+M  V30 9 1 2 8
+M  V30 END BOND
+M  V30 BEGIN COLLECTION
+M  V30 MDLV30/STERAC1 ATOMS=(1 2)
+M  V30 MDLV30/STEABS ATOMS=(1 4)
+M  V30 MDLV30/STERAC2 ATOMS=(1 8)
+M  V30 END COLLECTION
+M  V30 END CTAB
+M  END
+$$$$
+Structure drawings enhanced stereochemistry.sdf
+  ChemDraw01282608392D
+
+  0  0  0     0  0              0 V3000
+M  V30 BEGIN CTAB
+M  V30 COUNTS 9 9 0 0 0
+M  V30 BEGIN ATOM
+M  V30 1 O 0.824839 -1.071585 0.000000 0
+M  V30 2 C 0.412473 -0.357346 0.000000 0
+M  V30 3 C -0.412508 -0.357346 0.000000 0
+M  V30 4 C -0.824981 0.357119 0.000000 0
+M  V30 5 O -1.649713 0.357119 0.000000 0
+M  V30 6 C -0.412472 1.071585 0.000000 0
+M  V30 7 C 0.412510 1.071585 0.000000 0
+M  V30 8 C 0.824982 0.357119 0.000000 0
+M  V30 9 O 1.649713 0.357119 0.000000 0
+M  V30 END ATOM
+M  V30 BEGIN BOND
+M  V30 1 1 2 1 CFG=1
+M  V30 2 1 3 2
+M  V30 3 1 4 3
+M  V30 4 1 4 5 CFG=1
+M  V30 5 1 6 4
+M  V30 6 1 6 7
+M  V30 7 1 8 7
+M  V30 8 1 8 9 CFG=1
+M  V30 9 1 2 8
+M  V30 END BOND
+M  V30 BEGIN COLLECTION
+M  V30 MDLV30/STERAC1 ATOMS=(1 2)
+M  V30 MDLV30/STEABS ATOMS=(1 4)
+M  V30 MDLV30/STEREL1 ATOMS=(1 8)
+M  V30 END COLLECTION
+M  V30 END CTAB
+M  END
+$$$$
+Structure drawings enhanced stereochemistry.sdf
+  ChemDraw01282608392D
+
+  0  0  0     0  0              0 V3000
+M  V30 BEGIN CTAB
+M  V30 COUNTS 7 6 0 0 1
+M  V30 BEGIN ATOM
+M  V30 1 C 1.429261 -0.206312 0.000000 0
+M  V30 2 C 0.714577 0.206310 0.000000 0
+M  V30 3 C -0.000106 -0.206312 0.000000 0
+M  V30 4 N -0.000106 -1.031557 0.000000 0
+M  V30 5 C -0.714790 0.206310 0.000000 0
+M  V30 6 O -0.714790 1.031557 0.000000 0
+M  V30 7 C -1.429261 -0.206188 0.000000 0
+M  V30 END ATOM
+M  V30 BEGIN BOND
+M  V30 1 1 2 1
+M  V30 2 1 3 2
+M  V30 3 1 3 4
+M  V30 4 1 5 3
+M  V30 5 1 5 6 CFG=1
+M  V30 6 1 7 5
+M  V30 END BOND
+M  V30 END CTAB
+M  END
+$$$$
+Structure drawings enhanced stereochemistry.sdf
+  ChemDraw01282608392D
+
+  0  0  0     0  0              0 V3000
+M  V30 BEGIN CTAB
+M  V30 COUNTS 7 6 0 0 0
+M  V30 BEGIN ATOM
+M  V30 1 N -0.000106 -1.031556 0.000000 0
+M  V30 2 C -0.000106 -0.206312 0.000000 0
+M  V30 3 C 0.714577 0.206311 0.000000 0
+M  V30 4 C 1.429261 -0.206312 0.000000 0
+M  V30 5 C -0.714789 0.206311 0.000000 0
+M  V30 6 O -0.714789 1.031556 0.000000 0
+M  V30 7 C -1.429261 -0.206189 0.000000 0
+M  V30 END ATOM
+M  V30 BEGIN BOND
+M  V30 1 1 2 1
+M  V30 2 1 2 3
+M  V30 3 1 3 4
+M  V30 4 1 5 2
+M  V30 5 1 5 6 CFG=1
+M  V30 6 1 7 5
+M  V30 END BOND
+M  V30 BEGIN COLLECTION
+M  V30 MDLV30/STERAC1 ATOMS=(1 5)
+M  V30 END COLLECTION
+M  V30 END CTAB
+M  END
+$$$$
+Structure drawings enhanced stereochemistry.sdf
+  ChemDraw01282608392D
+
+  0  0  0     0  0              0 V3000
+M  V30 BEGIN CTAB
+M  V30 COUNTS 7 6 0 0 0
+M  V30 BEGIN ATOM
+M  V30 1 N -0.000106 -1.031556 0.000000 0
+M  V30 2 C -0.000106 -0.206312 0.000000 0
+M  V30 3 C 0.714577 0.206311 0.000000 0
+M  V30 4 C 1.429261 -0.206312 0.000000 0
+M  V30 5 C -0.714789 0.206311 0.000000 0
+M  V30 6 O -0.714789 1.031556 0.000000 0
+M  V30 7 C -1.429261 -0.206189 0.000000 0
+M  V30 END ATOM
+M  V30 BEGIN BOND
+M  V30 1 1 2 1
+M  V30 2 1 2 3
+M  V30 3 1 3 4
+M  V30 4 1 5 2
+M  V30 5 1 5 6 CFG=1
+M  V30 6 1 7 5
+M  V30 END BOND
+M  V30 BEGIN COLLECTION
+M  V30 MDLV30/STEREL1 ATOMS=(1 5)
+M  V30 END COLLECTION
+M  V30 END CTAB
+M  END
+$$$$
+Structure drawings enhanced stereochemistry.sdf
+  ChemDraw01282608392D
+
+  0  0  0     0  0              0 V3000
+M  V30 BEGIN CTAB
+M  V30 COUNTS 9 9 0 0 0
+M  V30 BEGIN ATOM
+M  V30 1 O 0.824839 -1.071585 0.000000 0
+M  V30 2 C 0.412473 -0.357346 0.000000 0
+M  V30 3 C -0.412508 -0.357346 0.000000 0
+M  V30 4 C -0.824981 0.357119 0.000000 0
+M  V30 5 O -1.649713 0.357119 0.000000 0
+M  V30 6 C -0.412472 1.071585 0.000000 0
+M  V30 7 C 0.412510 1.071585 0.000000 0
+M  V30 8 C 0.824982 0.357119 0.000000 0
+M  V30 9 O 1.649713 0.357119 0.000000 0
+M  V30 END ATOM
+M  V30 BEGIN BOND
+M  V30 1 1 2 1
+M  V30 2 1 3 2
+M  V30 3 1 4 3
+M  V30 4 1 4 5
+M  V30 5 1 6 4
+M  V30 6 1 6 7
+M  V30 7 1 8 7
+M  V30 8 1 8 9
+M  V30 9 1 2 8
+M  V30 END BOND
+M  V30 END CTAB
+M  END
+$$$$
diff --git a/INCHI-1-TEST/tests/test_unit/fixtures/enh_stereo_test_file_2.sdf b/INCHI-1-TEST/tests/test_unit/fixtures/enh_stereo_test_file_2.sdf
new file mode 100644
index 00000000..ef407954
--- /dev/null
+++ b/INCHI-1-TEST/tests/test_unit/fixtures/enh_stereo_test_file_2.sdf
@@ -0,0 +1,1972 @@
+
+  ACD/LABS08242216132D
+
+  0  0  0  0  0  0  0  0  0  0999 V3000
+M  V30 BEGIN CTAB
+M  V30 COUNTS 18 17 0 0 1
+M  V30 BEGIN ATOM
+M  V30 1 C 3424.1946 -1936.7935 0 0
+M  V30 2 C 3352.3145 -1895.2935 0 0
+M  V30 3 C 3280.4346 -1936.7935 0 0
+M  V30 4 C 3208.5542 -1895.2935 0 0
+M  V30 5 C 3136.6743 -1936.7935 0 0
+M  V30 6 C 3064.7944 -1895.2935 0 0
+M  V30 7 Br 3136.6743 -2019.7935 0 0
+M  V30 8 Cl 3208.5542 -1812.2935 0 0
+M  V30 9 Cl 3280.4346 -2019.7935 0 0
+M  V30 10 Cl 3352.3145 -1812.2935 0 0
+M  V30 11 Cl 3424.1946 -2019.7935 0 0
+M  V30 12 C 3496.075 -1895.2935 0 0
+M  V30 13 C 3567.9548 -1936.7942 0 0
+M  V30 14 C 3639.835 -1895.2944 0 0
+M  V30 15 C 3711.7148 -1936.7942 0 0
+M  V30 16 Cl 3639.835 -1812.2944 0 0
+M  V30 17 Cl 3567.9548 -2019.7942 0 0
+M  V30 18 Cl 3496.075 -1812.2937 0 0
+M  V30 END ATOM
+M  V30 BEGIN BOND
+M  V30 1 1 1 2
+M  V30 2 1 1 11 CFG=3
+M  V30 3 1 1 12
+M  V30 4 1 2 3
+M  V30 5 1 2 10 CFG=1
+M  V30 6 1 3 4
+M  V30 7 1 3 9 CFG=1
+M  V30 8 1 4 5
+M  V30 9 1 4 8 CFG=1
+M  V30 10 1 5 6
+M  V30 11 1 5 7 CFG=1
+M  V30 12 1 12 13
+M  V30 13 1 12 18 CFG=3
+M  V30 14 1 13 14
+M  V30 15 1 13 17 CFG=1
+M  V30 16 1 14 15
+M  V30 17 1 14 16 CFG=1
+M  V30 END BOND
+M  V30 BEGIN COLLECTION
+M  V30 MDLV30/STERAC2 ATOMS=(1 1)
+M  V30 MDLV30/STERAC1 ATOMS=(2 2 3)
+M  V30 MDLV30/STEABS ATOMS=(2 4 5)
+M  V30 MDLV30/STEREL1 ATOMS=(2 12 13)
+M  V30 MDLV30/STEREL2 ATOMS=(1 14)
+M  V30 END COLLECTION
+M  V30 END CTAB
+M  END
+>  <InChI>
+InChI=1S/C10H14BrCl7/c1-3(11)5(13)7(15)9(17)10(18)8(16)6(14)4(2)12/h3-10H,1-2H3/t3-,4-,5+,6+,7-,8+,9+,10-/m0/s1
+
+>  <InChI_new>
+InChI=1S/C10H14BrCl7/c1-3(11)5(13)7(15)9(17)10(18)8(16)6(14)4(2)12/h3-10H,1-2H3/t3-,4-,5+,6-,7-,8-,9+,10-/m0/s1(3,5)2(4)(6,8)3(7,9)(10)
+
+>  <Isomer>
+1EN
+
+$$$$
+
+  ACD/LABS08242216132D
+
+  0  0  0  0  0  0  0  0  0  0999 V3000
+M  V30 BEGIN CTAB
+M  V30 COUNTS 18 17 0 0 1
+M  V30 BEGIN ATOM
+M  V30 1 C 2617.5557 -1933.6348 0 0
+M  V30 2 C 2545.6758 -1892.1348 0 0
+M  V30 3 C 2473.7957 -1933.6348 0 0
+M  V30 4 C 2401.9155 -1892.1348 0 0
+M  V30 5 C 2330.0354 -1933.6348 0 0
+M  V30 6 C 2258.1553 -1892.1348 0 0
+M  V30 7 Br 2330.0354 -2016.6348 0 0
+M  V30 8 Cl 2401.9155 -1809.1348 0 0
+M  V30 9 Cl 2473.7957 -2016.6348 0 0
+M  V30 10 Cl 2545.6758 -1809.1348 0 0
+M  V30 11 Cl 2617.5557 -2016.6348 0 0
+M  V30 12 C 2689.436 -1892.1348 0 0
+M  V30 13 C 2761.3159 -1933.6355 0 0
+M  V30 14 C 2833.1958 -1892.1357 0 0
+M  V30 15 C 2905.0759 -1933.6355 0 0
+M  V30 16 Cl 2833.1958 -1809.1357 0 0
+M  V30 17 Cl 2761.3159 -2016.6355 0 0
+M  V30 18 Cl 2689.436 -1809.135 0 0
+M  V30 END ATOM
+M  V30 BEGIN BOND
+M  V30 1 1 1 2
+M  V30 2 1 1 11 CFG=1
+M  V30 3 1 1 12
+M  V30 4 1 2 3
+M  V30 5 1 2 10 CFG=1
+M  V30 6 1 3 4
+M  V30 7 1 3 9 CFG=1
+M  V30 8 1 4 5
+M  V30 9 1 4 8 CFG=1
+M  V30 10 1 5 6
+M  V30 11 1 5 7 CFG=1
+M  V30 12 1 12 13
+M  V30 13 1 12 18 CFG=3
+M  V30 14 1 13 14
+M  V30 15 1 13 17 CFG=1
+M  V30 16 1 14 15
+M  V30 17 1 14 16 CFG=1
+M  V30 END BOND
+M  V30 BEGIN COLLECTION
+M  V30 MDLV30/STERAC2 ATOMS=(1 1)
+M  V30 MDLV30/STERAC1 ATOMS=(2 2 3)
+M  V30 MDLV30/STEABS ATOMS=(2 4 5)
+M  V30 MDLV30/STEREL1 ATOMS=(2 12 13)
+M  V30 MDLV30/STEREL2 ATOMS=(1 14)
+M  V30 END COLLECTION
+M  V30 END CTAB
+M  END
+>  <InChI>
+InChI=1S/C10H14BrCl7/c1-3(11)5(13)7(15)9(17)10(18)8(16)6(14)4(2)12/h3-10H,1-2H3/t3-,4-,5+,6+,7-,8+,9+,10+/m0/s1
+
+>  <InChI_new>
+InChI=1S/C10H14BrCl7/c1-3(11)5(13)7(15)9(17)10(18)8(16)6(14)4(2)12/h3-10H,1-2H3/t3-,4-,5+,6-,7-,8-,9+,10-/m0/s1(3,5)2(4)(6,8)3(7,9)(10)
+
+>  <Isomer>
+1EN
+
+$$$$
+
+  ACD/LABS08242216132D
+
+  0  0  0  0  0  0  0  0  0  0999 V3000
+M  V30 BEGIN CTAB
+M  V30 COUNTS 18 17 0 0 1
+M  V30 BEGIN ATOM
+M  V30 1 C 1652.5557 -1930.6348 0 0
+M  V30 2 C 1580.6757 -1889.1348 0 0
+M  V30 3 C 1508.7957 -1930.6348 0 0
+M  V30 4 C 1436.9154 -1889.1348 0 0
+M  V30 5 C 1365.0354 -1930.6348 0 0
+M  V30 6 C 1293.1554 -1889.1348 0 0
+M  V30 7 Br 1365.0354 -2013.6348 0 0
+M  V30 8 Cl 1436.9154 -1806.1348 0 0
+M  V30 9 Cl 1508.7957 -2013.6348 0 0
+M  V30 10 Cl 1580.6757 -1806.1348 0 0
+M  V30 11 Cl 1652.5557 -2013.6348 0 0
+M  V30 12 C 1724.436 -1889.1348 0 0
+M  V30 13 C 1796.3159 -1930.6355 0 0
+M  V30 14 C 1868.196 -1889.1357 0 0
+M  V30 15 C 1940.0759 -1930.6355 0 0
+M  V30 16 Cl 1868.196 -1806.1357 0 0
+M  V30 17 Cl 1796.3159 -2013.6355 0 0
+M  V30 18 Cl 1724.436 -1806.135 0 0
+M  V30 END ATOM
+M  V30 BEGIN BOND
+M  V30 1 1 1 2
+M  V30 2 1 1 11 CFG=3
+M  V30 3 1 1 12
+M  V30 4 1 2 3
+M  V30 5 1 2 10 CFG=1
+M  V30 6 1 3 4
+M  V30 7 1 3 9 CFG=1
+M  V30 8 1 4 5
+M  V30 9 1 4 8 CFG=1
+M  V30 10 1 5 6
+M  V30 11 1 5 7 CFG=1
+M  V30 12 1 12 13
+M  V30 13 1 12 18 CFG=1
+M  V30 14 1 13 14
+M  V30 15 1 13 17 CFG=3
+M  V30 16 1 14 15
+M  V30 17 1 14 16 CFG=1
+M  V30 END BOND
+M  V30 BEGIN COLLECTION
+M  V30 MDLV30/STERAC2 ATOMS=(1 1)
+M  V30 MDLV30/STERAC1 ATOMS=(2 2 3)
+M  V30 MDLV30/STEABS ATOMS=(2 4 5)
+M  V30 MDLV30/STEREL1 ATOMS=(2 12 13)
+M  V30 MDLV30/STEREL2 ATOMS=(1 14)
+M  V30 END COLLECTION
+M  V30 END CTAB
+M  END
+>  <InChI>
+InChI=1S/C10H14BrCl7/c1-3(11)5(13)7(15)9(17)10(18)8(16)6(14)4(2)12/h3-10H,1-2H3/t3-,4-,5+,6-,7-,8-,9+,10-/m0/s1
+
+>  <InChI_new>
+InChI=1S/C10H14BrCl7/c1-3(11)5(13)7(15)9(17)10(18)8(16)6(14)4(2)12/h3-10H,1-2H3/t3-,4-,5+,6-,7-,8-,9+,10-/m0/s1(3,5)2(4)(6,8)3(7,9)(10)
+
+>  <Isomer>
+1EN
+
+$$$$
+
+  ACD/LABS08242216132D
+
+  0  0  0  0  0  0  0  0  0  0999 V3000
+M  V30 BEGIN CTAB
+M  V30 COUNTS 18 17 0 0 1
+M  V30 BEGIN ATOM
+M  V30 1 C 845.9167 -1927.4761 0 0
+M  V30 2 C 774.0367 -1885.9761 0 0
+M  V30 3 C 702.1567 -1927.4761 0 0
+M  V30 4 C 630.2765 -1885.9761 0 0
+M  V30 5 C 558.3965 -1927.4761 0 0
+M  V30 6 C 486.5165 -1885.9761 0 0
+M  V30 7 Br 558.3965 -2010.4761 0 0
+M  V30 8 Cl 630.2765 -1802.9761 0 0
+M  V30 9 Cl 702.1567 -2010.4761 0 0
+M  V30 10 Cl 774.0367 -1802.9761 0 0
+M  V30 11 Cl 845.9167 -2010.4761 0 0
+M  V30 12 C 917.7971 -1885.9761 0 0
+M  V30 13 C 989.677 -1927.4768 0 0
+M  V30 14 C 1061.557 -1885.9771 0 0
+M  V30 15 C 1133.437 -1927.4768 0 0
+M  V30 16 Cl 1061.557 -1802.9771 0 0
+M  V30 17 Cl 989.677 -2010.4768 0 0
+M  V30 18 Cl 917.7971 -1802.9763 0 0
+M  V30 END ATOM
+M  V30 BEGIN BOND
+M  V30 1 1 1 2
+M  V30 2 1 1 11 CFG=1
+M  V30 3 1 1 12
+M  V30 4 1 2 3
+M  V30 5 1 2 10 CFG=1
+M  V30 6 1 3 4
+M  V30 7 1 3 9 CFG=1
+M  V30 8 1 4 5
+M  V30 9 1 4 8 CFG=1
+M  V30 10 1 5 6
+M  V30 11 1 5 7 CFG=1
+M  V30 12 1 12 13
+M  V30 13 1 12 18 CFG=1
+M  V30 14 1 13 14
+M  V30 15 1 13 17 CFG=3
+M  V30 16 1 14 15
+M  V30 17 1 14 16 CFG=1
+M  V30 END BOND
+M  V30 BEGIN COLLECTION
+M  V30 MDLV30/STERAC2 ATOMS=(1 1)
+M  V30 MDLV30/STERAC1 ATOMS=(2 2 3)
+M  V30 MDLV30/STEABS ATOMS=(2 4 5)
+M  V30 MDLV30/STEREL1 ATOMS=(2 12 13)
+M  V30 MDLV30/STEREL2 ATOMS=(1 14)
+M  V30 END COLLECTION
+M  V30 END CTAB
+M  END
+>  <InChI>
+InChI=1S/C10H14BrCl7/c1-3(11)5(13)7(15)9(17)10(18)8(16)6(14)4(2)12/h3-10H,1-2H3/t3-,4-,5+,6-,7-,8-,9+,10+/m0/s1
+
+>  <InChI_new>
+InChI=1S/C10H14BrCl7/c1-3(11)5(13)7(15)9(17)10(18)8(16)6(14)4(2)12/h3-10H,1-2H3/t3-,4-,5+,6-,7-,8-,9+,10-/m0/s1(3,5)2(4)(6,8)3(7,9)(10)
+
+>  <Isomer>
+1EN
+
+$$$$
+
+  ACD/LABS08242216132D
+
+  0  0  0  0  0  0  0  0  0  0999 V3000
+M  V30 BEGIN CTAB
+M  V30 COUNTS 18 17 0 0 1
+M  V30 BEGIN ATOM
+M  V30 1 C 3436.5557 -1571.6348 0 0
+M  V30 2 C 3364.6758 -1530.1348 0 0
+M  V30 3 C 3292.7957 -1571.6348 0 0
+M  V30 4 C 3220.9155 -1530.1348 0 0
+M  V30 5 C 3149.0354 -1571.6348 0 0
+M  V30 6 C 3077.1553 -1530.1348 0 0
+M  V30 7 Br 3149.0354 -1654.6346 0 0
+M  V30 8 Cl 3220.9155 -1447.1348 0 0
+M  V30 9 Cl 3292.7957 -1654.6346 0 0
+M  V30 10 Cl 3364.6758 -1447.1348 0 0
+M  V30 11 Cl 3436.5557 -1654.6346 0 0
+M  V30 12 C 3508.436 -1530.1349 0 0
+M  V30 13 C 3580.3159 -1571.6355 0 0
+M  V30 14 C 3652.1958 -1530.1356 0 0
+M  V30 15 C 3724.0759 -1571.6355 0 0
+M  V30 16 Cl 3652.1958 -1447.1356 0 0
+M  V30 17 Cl 3580.3159 -1654.6355 0 0
+M  V30 18 Cl 3508.436 -1447.135 0 0
+M  V30 END ATOM
+M  V30 BEGIN BOND
+M  V30 1 1 1 2
+M  V30 2 1 1 11 CFG=3
+M  V30 3 1 1 12
+M  V30 4 1 2 3
+M  V30 5 1 2 10 CFG=1
+M  V30 6 1 3 4
+M  V30 7 1 3 9 CFG=1
+M  V30 8 1 4 5
+M  V30 9 1 4 8 CFG=1
+M  V30 10 1 5 6
+M  V30 11 1 5 7 CFG=1
+M  V30 12 1 12 13
+M  V30 13 1 12 18 CFG=3
+M  V30 14 1 13 14
+M  V30 15 1 13 17 CFG=1
+M  V30 16 1 14 15
+M  V30 17 1 14 16 CFG=3
+M  V30 END BOND
+M  V30 BEGIN COLLECTION
+M  V30 MDLV30/STERAC2 ATOMS=(1 1)
+M  V30 MDLV30/STERAC1 ATOMS=(2 2 3)
+M  V30 MDLV30/STEABS ATOMS=(2 4 5)
+M  V30 MDLV30/STEREL1 ATOMS=(2 12 13)
+M  V30 MDLV30/STEREL2 ATOMS=(1 14)
+M  V30 END COLLECTION
+M  V30 END CTAB
+M  END
+>  <InChI>
+InChI=1S/C10H14BrCl7/c1-3(11)5(13)7(15)9(17)10(18)8(16)6(14)4(2)12/h3-10H,1-2H3/t3-,4+,5+,6+,7-,8+,9+,10-/m0/s1
+
+>  <InChI_new>
+InChI=1S/C10H14BrCl7/c1-3(11)5(13)7(15)9(17)10(18)8(16)6(14)4(2)12/h3-10H,1-2H3/t3-,4-,5+,6-,7-,8-,9+,10-/m0/s1(3,5)2(4)(6,8)3(7,9)(10)
+
+>  <Isomer>
+1EN
+
+$$$$
+
+  ACD/LABS08242216132D
+
+  0  0  0  0  0  0  0  0  0  0999 V3000
+M  V30 BEGIN CTAB
+M  V30 COUNTS 18 17 0 0 1
+M  V30 BEGIN ATOM
+M  V30 1 C 2629.9167 -1568.4761 0 0
+M  V30 2 C 2558.0366 -1526.9761 0 0
+M  V30 3 C 2486.1567 -1568.4761 0 0
+M  V30 4 C 2414.2764 -1526.9761 0 0
+M  V30 5 C 2342.3965 -1568.4761 0 0
+M  V30 6 C 2270.5166 -1526.9761 0 0
+M  V30 7 Br 2342.3965 -1651.476 0 0
+M  V30 8 Cl 2414.2764 -1443.9761 0 0
+M  V30 9 Cl 2486.1567 -1651.476 0 0
+M  V30 10 Cl 2558.0366 -1443.9761 0 0
+M  V30 11 Cl 2629.9167 -1651.476 0 0
+M  V30 12 C 2701.7971 -1526.9762 0 0
+M  V30 13 C 2773.677 -1568.4768 0 0
+M  V30 14 C 2845.5571 -1526.9769 0 0
+M  V30 15 C 2917.437 -1568.4768 0 0
+M  V30 16 Cl 2845.5571 -1443.9769 0 0
+M  V30 17 Cl 2773.677 -1651.4768 0 0
+M  V30 18 Cl 2701.7971 -1443.9763 0 0
+M  V30 END ATOM
+M  V30 BEGIN BOND
+M  V30 1 1 1 2
+M  V30 2 1 1 11 CFG=1
+M  V30 3 1 1 12
+M  V30 4 1 2 3
+M  V30 5 1 2 10 CFG=1
+M  V30 6 1 3 4
+M  V30 7 1 3 9 CFG=1
+M  V30 8 1 4 5
+M  V30 9 1 4 8 CFG=1
+M  V30 10 1 5 6
+M  V30 11 1 5 7 CFG=1
+M  V30 12 1 12 13
+M  V30 13 1 12 18 CFG=3
+M  V30 14 1 13 14
+M  V30 15 1 13 17 CFG=1
+M  V30 16 1 14 15
+M  V30 17 1 14 16 CFG=3
+M  V30 END BOND
+M  V30 BEGIN COLLECTION
+M  V30 MDLV30/STERAC2 ATOMS=(1 1)
+M  V30 MDLV30/STERAC1 ATOMS=(2 2 3)
+M  V30 MDLV30/STEABS ATOMS=(2 4 5)
+M  V30 MDLV30/STEREL1 ATOMS=(2 12 13)
+M  V30 MDLV30/STEREL2 ATOMS=(1 14)
+M  V30 END COLLECTION
+M  V30 END CTAB
+M  END
+>  <InChI>
+InChI=1S/C10H14BrCl7/c1-3(11)5(13)7(15)9(17)10(18)8(16)6(14)4(2)12/h3-10H,1-2H3/t3-,4+,5+,6+,7-,8+,9+,10+/m0/s1
+
+>  <InChI_new>
+InChI=1S/C10H14BrCl7/c1-3(11)5(13)7(15)9(17)10(18)8(16)6(14)4(2)12/h3-10H,1-2H3/t3-,4-,5+,6-,7-,8-,9+,10-/m0/s1(3,5)2(4)(6,8)3(7,9)(10)
+
+>  <Isomer>
+1EN
+
+$$$$
+
+  ACD/LABS08242216132D
+
+  0  0  0  0  0  0  0  0  0  0999 V3000
+M  V30 BEGIN CTAB
+M  V30 COUNTS 18 17 0 0 1
+M  V30 BEGIN ATOM
+M  V30 1 C 1664.9167 -1565.4761 0 0
+M  V30 2 C 1593.0367 -1523.9761 0 0
+M  V30 3 C 1521.1567 -1565.4761 0 0
+M  V30 4 C 1449.2765 -1523.9761 0 0
+M  V30 5 C 1377.3965 -1565.4761 0 0
+M  V30 6 C 1305.5165 -1523.9761 0 0
+M  V30 7 Br 1377.3965 -1648.476 0 0
+M  V30 8 Cl 1449.2765 -1440.9761 0 0
+M  V30 9 Cl 1521.1567 -1648.476 0 0
+M  V30 10 Cl 1593.0367 -1440.9761 0 0
+M  V30 11 Cl 1664.9167 -1648.476 0 0
+M  V30 12 C 1736.7971 -1523.9762 0 0
+M  V30 13 C 1808.677 -1565.4768 0 0
+M  V30 14 C 1880.5569 -1523.9769 0 0
+M  V30 15 C 1952.437 -1565.4768 0 0
+M  V30 16 Cl 1880.5569 -1440.9769 0 0
+M  V30 17 Cl 1808.677 -1648.4768 0 0
+M  V30 18 Cl 1736.7971 -1440.9763 0 0
+M  V30 END ATOM
+M  V30 BEGIN BOND
+M  V30 1 1 1 2
+M  V30 2 1 1 11 CFG=3
+M  V30 3 1 1 12
+M  V30 4 1 2 3
+M  V30 5 1 2 10 CFG=1
+M  V30 6 1 3 4
+M  V30 7 1 3 9 CFG=1
+M  V30 8 1 4 5
+M  V30 9 1 4 8 CFG=1
+M  V30 10 1 5 6
+M  V30 11 1 5 7 CFG=1
+M  V30 12 1 12 13
+M  V30 13 1 12 18 CFG=1
+M  V30 14 1 13 14
+M  V30 15 1 13 17 CFG=3
+M  V30 16 1 14 15
+M  V30 17 1 14 16 CFG=3
+M  V30 END BOND
+M  V30 BEGIN COLLECTION
+M  V30 MDLV30/STERAC2 ATOMS=(1 1)
+M  V30 MDLV30/STERAC1 ATOMS=(2 2 3)
+M  V30 MDLV30/STEABS ATOMS=(2 4 5)
+M  V30 MDLV30/STEREL1 ATOMS=(2 12 13)
+M  V30 MDLV30/STEREL2 ATOMS=(1 14)
+M  V30 END COLLECTION
+M  V30 END CTAB
+M  END
+>  <InChI>
+InChI=1S/C10H14BrCl7/c1-3(11)5(13)7(15)9(17)10(18)8(16)6(14)4(2)12/h3-10H,1-2H3/t3-,4+,5+,6-,7-,8-,9+,10-/m0/s1
+
+>  <InChI_new>
+InChI=1S/C10H14BrCl7/c1-3(11)5(13)7(15)9(17)10(18)8(16)6(14)4(2)12/h3-10H,1-2H3/t3-,4-,5+,6-,7-,8-,9+,10-/m0/s1(3,5)2(4)(6,8)3(7,9)(10)
+
+>  <Isomer>
+1EN
+
+$$$$
+
+  ACD/LABS08242216132D
+
+  0  0  0  0  0  0  0  0  0  0999 V3000
+M  V30 BEGIN CTAB
+M  V30 COUNTS 18 17 0 0 1
+M  V30 BEGIN ATOM
+M  V30 1 C 858.2778 -1562.3174 0 0
+M  V30 2 C 786.3978 -1520.8174 0 0
+M  V30 3 C 714.5178 -1562.3174 0 0
+M  V30 4 C 642.6376 -1520.8174 0 0
+M  V30 5 C 570.7576 -1562.3174 0 0
+M  V30 6 C 498.8776 -1520.8174 0 0
+M  V30 7 Br 570.7576 -1645.3173 0 0
+M  V30 8 Cl 642.6376 -1437.8174 0 0
+M  V30 9 Cl 714.5178 -1645.3173 0 0
+M  V30 10 Cl 786.3978 -1437.8174 0 0
+M  V30 11 Cl 858.2778 -1645.3173 0 0
+M  V30 12 C 930.1582 -1520.8175 0 0
+M  V30 13 C 1002.0381 -1562.3181 0 0
+M  V30 14 C 1073.9181 -1520.8182 0 0
+M  V30 15 C 1145.7981 -1562.3181 0 0
+M  V30 16 Cl 1073.9181 -1437.8182 0 0
+M  V30 17 Cl 1002.0381 -1645.3181 0 0
+M  V30 18 Cl 930.1582 -1437.8176 0 0
+M  V30 END ATOM
+M  V30 BEGIN BOND
+M  V30 1 1 1 2
+M  V30 2 1 1 11 CFG=1
+M  V30 3 1 1 12
+M  V30 4 1 2 3
+M  V30 5 1 2 10 CFG=1
+M  V30 6 1 3 4
+M  V30 7 1 3 9 CFG=1
+M  V30 8 1 4 5
+M  V30 9 1 4 8 CFG=1
+M  V30 10 1 5 6
+M  V30 11 1 5 7 CFG=1
+M  V30 12 1 12 13
+M  V30 13 1 12 18 CFG=1
+M  V30 14 1 13 14
+M  V30 15 1 13 17 CFG=3
+M  V30 16 1 14 15
+M  V30 17 1 14 16 CFG=3
+M  V30 END BOND
+M  V30 BEGIN COLLECTION
+M  V30 MDLV30/STERAC2 ATOMS=(1 1)
+M  V30 MDLV30/STERAC1 ATOMS=(2 2 3)
+M  V30 MDLV30/STEABS ATOMS=(2 4 5)
+M  V30 MDLV30/STEREL1 ATOMS=(2 12 13)
+M  V30 MDLV30/STEREL2 ATOMS=(1 14)
+M  V30 END COLLECTION
+M  V30 END CTAB
+M  END
+>  <InChI>
+InChI=1S/C10H14BrCl7/c1-3(11)5(13)7(15)9(17)10(18)8(16)6(14)4(2)12/h3-10H,1-2H3/t3-,4+,5+,6-,7-,8-,9+,10+/m0/s1
+
+>  <InChI_new>
+InChI=1S/C10H14BrCl7/c1-3(11)5(13)7(15)9(17)10(18)8(16)6(14)4(2)12/h3-10H,1-2H3/t3-,4-,5+,6-,7-,8-,9+,10-/m0/s1(3,5)2(4)(6,8)3(7,9)(10)
+
+>  <Isomer>
+1EN
+
+$$$$
+
+  ACD/LABS08242216132D
+
+  0  0  0  0  0  0  0  0  0  0999 V3000
+M  V30 BEGIN CTAB
+M  V30 COUNTS 18 17 0 0 1
+M  V30 BEGIN ATOM
+M  V30 1 C 3428.5557 -1046.6348 0 0
+M  V30 2 C 3356.6758 -1005.1348 0 0
+M  V30 3 C 3284.7957 -1046.6348 0 0
+M  V30 4 C 3212.9155 -1005.1348 0 0
+M  V30 5 C 3141.0354 -1046.6348 0 0
+M  V30 6 C 3069.1553 -1005.1348 0 0
+M  V30 7 Br 3141.0354 -1129.6346 0 0
+M  V30 8 Cl 3212.9155 -922.1348 0 0
+M  V30 9 Cl 3284.7957 -1129.6346 0 0
+M  V30 10 Cl 3356.6758 -922.1348 0 0
+M  V30 11 Cl 3428.5557 -1129.6346 0 0
+M  V30 12 C 3500.436 -1005.1349 0 0
+M  V30 13 C 3572.3159 -1046.6355 0 0
+M  V30 14 C 3644.196 -1005.1356 0 0
+M  V30 15 C 3716.0759 -1046.6355 0 0
+M  V30 16 Cl 3644.196 -922.1356 0 0
+M  V30 17 Cl 3572.3159 -1129.6355 0 0
+M  V30 18 Cl 3500.436 -922.135 0 0
+M  V30 END ATOM
+M  V30 BEGIN BOND
+M  V30 1 1 1 2
+M  V30 2 1 1 11 CFG=3
+M  V30 3 1 1 12
+M  V30 4 1 2 3
+M  V30 5 1 2 10 CFG=3
+M  V30 6 1 3 4
+M  V30 7 1 3 9 CFG=3
+M  V30 8 1 4 5
+M  V30 9 1 4 8 CFG=1
+M  V30 10 1 5 6
+M  V30 11 1 5 7 CFG=1
+M  V30 12 1 12 13
+M  V30 13 1 12 18 CFG=3
+M  V30 14 1 13 14
+M  V30 15 1 13 17 CFG=1
+M  V30 16 1 14 15
+M  V30 17 1 14 16 CFG=1
+M  V30 END BOND
+M  V30 BEGIN COLLECTION
+M  V30 MDLV30/STERAC2 ATOMS=(1 1)
+M  V30 MDLV30/STERAC1 ATOMS=(2 2 3)
+M  V30 MDLV30/STEABS ATOMS=(2 4 5)
+M  V30 MDLV30/STEREL1 ATOMS=(2 12 13)
+M  V30 MDLV30/STEREL2 ATOMS=(1 14)
+M  V30 END COLLECTION
+M  V30 END CTAB
+M  END
+>  <InChI>
+InChI=1S/C10H14BrCl7/c1-3(11)5(13)7(15)9(17)10(18)8(16)6(14)4(2)12/h3-10H,1-2H3/t3-,4-,5+,6+,7+,8+,9-,10-/m0/s1
+
+>  <InChI_new>
+InChI=1S/C10H14BrCl7/c1-3(11)5(13)7(15)9(17)10(18)8(16)6(14)4(2)12/h3-10H,1-2H3/t3-,4-,5+,6-,7-,8-,9+,10-/m0/s1(3,5)2(4)(6,8)3(7,9)(10)
+
+>  <Isomer>
+1EN
+
+$$$$
+
+  ACD/LABS08242216132D
+
+  0  0  0  0  0  0  0  0  0  0999 V3000
+M  V30 BEGIN CTAB
+M  V30 COUNTS 18 17 0 0 1
+M  V30 BEGIN ATOM
+M  V30 1 C 2621.9167 -1043.4761 0 0
+M  V30 2 C 2550.0366 -1001.9761 0 0
+M  V30 3 C 2478.1567 -1043.4761 0 0
+M  V30 4 C 2406.2764 -1001.9761 0 0
+M  V30 5 C 2334.3965 -1043.4761 0 0
+M  V30 6 C 2262.5166 -1001.9761 0 0
+M  V30 7 Br 2334.3965 -1126.476 0 0
+M  V30 8 Cl 2406.2764 -918.9761 0 0
+M  V30 9 Cl 2478.1567 -1126.476 0 0
+M  V30 10 Cl 2550.0366 -918.9761 0 0
+M  V30 11 Cl 2621.9167 -1126.476 0 0
+M  V30 12 C 2693.7971 -1001.9762 0 0
+M  V30 13 C 2765.677 -1043.4768 0 0
+M  V30 14 C 2837.5571 -1001.9769 0 0
+M  V30 15 C 2909.437 -1043.4768 0 0
+M  V30 16 Cl 2837.5571 -918.9769 0 0
+M  V30 17 Cl 2765.677 -1126.4768 0 0
+M  V30 18 Cl 2693.7971 -918.9763 0 0
+M  V30 END ATOM
+M  V30 BEGIN BOND
+M  V30 1 1 1 2
+M  V30 2 1 1 11 CFG=1
+M  V30 3 1 1 12
+M  V30 4 1 2 3
+M  V30 5 1 2 10 CFG=3
+M  V30 6 1 3 4
+M  V30 7 1 3 9 CFG=3
+M  V30 8 1 4 5
+M  V30 9 1 4 8 CFG=1
+M  V30 10 1 5 6
+M  V30 11 1 5 7 CFG=1
+M  V30 12 1 12 13
+M  V30 13 1 12 18 CFG=3
+M  V30 14 1 13 14
+M  V30 15 1 13 17 CFG=1
+M  V30 16 1 14 15
+M  V30 17 1 14 16 CFG=1
+M  V30 END BOND
+M  V30 BEGIN COLLECTION
+M  V30 MDLV30/STERAC2 ATOMS=(1 1)
+M  V30 MDLV30/STERAC1 ATOMS=(2 2 3)
+M  V30 MDLV30/STEABS ATOMS=(2 4 5)
+M  V30 MDLV30/STEREL1 ATOMS=(2 12 13)
+M  V30 MDLV30/STEREL2 ATOMS=(1 14)
+M  V30 END COLLECTION
+M  V30 END CTAB
+M  END
+>  <InChI>
+InChI=1S/C10H14BrCl7/c1-3(11)5(13)7(15)9(17)10(18)8(16)6(14)4(2)12/h3-10H,1-2H3/t3-,4-,5+,6+,7+,8+,9-,10+/m0/s1
+
+>  <InChI_new>
+InChI=1S/C10H14BrCl7/c1-3(11)5(13)7(15)9(17)10(18)8(16)6(14)4(2)12/h3-10H,1-2H3/t3-,4-,5+,6-,7-,8-,9+,10-/m0/s1(3,5)2(4)(6,8)3(7,9)(10)
+
+>  <Isomer>
+1EN
+
+$$$$
+
+  ACD/LABS08242216132D
+
+  0  0  0  0  0  0  0  0  0  0999 V3000
+M  V30 BEGIN CTAB
+M  V30 COUNTS 18 17 0 0 1
+M  V30 BEGIN ATOM
+M  V30 1 C 1656.9167 -1040.4761 0 0
+M  V30 2 C 1585.0367 -998.9761 0 0
+M  V30 3 C 1513.1567 -1040.4761 0 0
+M  V30 4 C 1441.2765 -998.9761 0 0
+M  V30 5 C 1369.3965 -1040.4761 0 0
+M  V30 6 C 1297.5165 -998.9761 0 0
+M  V30 7 Br 1369.3965 -1123.476 0 0
+M  V30 8 Cl 1441.2765 -915.9761 0 0
+M  V30 9 Cl 1513.1567 -1123.476 0 0
+M  V30 10 Cl 1585.0367 -915.9761 0 0
+M  V30 11 Cl 1656.9167 -1123.476 0 0
+M  V30 12 C 1728.7971 -998.9762 0 0
+M  V30 13 C 1800.677 -1040.4768 0 0
+M  V30 14 C 1872.5571 -998.9769 0 0
+M  V30 15 C 1944.437 -1040.4768 0 0
+M  V30 16 Cl 1872.5571 -915.9769 0 0
+M  V30 17 Cl 1800.677 -1123.4768 0 0
+M  V30 18 Cl 1728.7971 -915.9763 0 0
+M  V30 END ATOM
+M  V30 BEGIN BOND
+M  V30 1 1 1 2
+M  V30 2 1 1 11 CFG=3
+M  V30 3 1 1 12
+M  V30 4 1 2 3
+M  V30 5 1 2 10 CFG=3
+M  V30 6 1 3 4
+M  V30 7 1 3 9 CFG=3
+M  V30 8 1 4 5
+M  V30 9 1 4 8 CFG=1
+M  V30 10 1 5 6
+M  V30 11 1 5 7 CFG=1
+M  V30 12 1 12 13
+M  V30 13 1 12 18 CFG=1
+M  V30 14 1 13 14
+M  V30 15 1 13 17 CFG=3
+M  V30 16 1 14 15
+M  V30 17 1 14 16 CFG=1
+M  V30 END BOND
+M  V30 BEGIN COLLECTION
+M  V30 MDLV30/STERAC2 ATOMS=(1 1)
+M  V30 MDLV30/STERAC1 ATOMS=(2 2 3)
+M  V30 MDLV30/STEABS ATOMS=(2 4 5)
+M  V30 MDLV30/STEREL1 ATOMS=(2 12 13)
+M  V30 MDLV30/STEREL2 ATOMS=(1 14)
+M  V30 END COLLECTION
+M  V30 END CTAB
+M  END
+>  <InChI>
+InChI=1S/C10H14BrCl7/c1-3(11)5(13)7(15)9(17)10(18)8(16)6(14)4(2)12/h3-10H,1-2H3/t3-,4-,5+,6-,7+,8-,9-,10-/m0/s1
+
+>  <InChI_new>
+InChI=1S/C10H14BrCl7/c1-3(11)5(13)7(15)9(17)10(18)8(16)6(14)4(2)12/h3-10H,1-2H3/t3-,4-,5+,6-,7-,8-,9+,10-/m0/s1(3,5)2(4)(6,8)3(7,9)(10)
+
+>  <Isomer>
+1EN
+
+$$$$
+
+  ACD/LABS08242216132D
+
+  0  0  0  0  0  0  0  0  0  0999 V3000
+M  V30 BEGIN CTAB
+M  V30 COUNTS 18 17 0 0 1
+M  V30 BEGIN ATOM
+M  V30 1 C 850.2778 -1037.3174 0 0
+M  V30 2 C 778.3978 -995.8174 0 0
+M  V30 3 C 706.5178 -1037.3174 0 0
+M  V30 4 C 634.6376 -995.8174 0 0
+M  V30 5 C 562.7576 -1037.3174 0 0
+M  V30 6 C 490.8776 -995.8174 0 0
+M  V30 7 Br 562.7576 -1120.3173 0 0
+M  V30 8 Cl 634.6376 -912.8174 0 0
+M  V30 9 Cl 706.5178 -1120.3173 0 0
+M  V30 10 Cl 778.3978 -912.8174 0 0
+M  V30 11 Cl 850.2778 -1120.3173 0 0
+M  V30 12 C 922.1582 -995.8175 0 0
+M  V30 13 C 994.0381 -1037.3181 0 0
+M  V30 14 C 1065.9181 -995.8182 0 0
+M  V30 15 C 1137.7981 -1037.3181 0 0
+M  V30 16 Cl 1065.9181 -912.8182 0 0
+M  V30 17 Cl 994.0381 -1120.3181 0 0
+M  V30 18 Cl 922.1582 -912.8176 0 0
+M  V30 END ATOM
+M  V30 BEGIN BOND
+M  V30 1 1 1 2
+M  V30 2 1 1 11 CFG=1
+M  V30 3 1 1 12
+M  V30 4 1 2 3
+M  V30 5 1 2 10 CFG=3
+M  V30 6 1 3 4
+M  V30 7 1 3 9 CFG=3
+M  V30 8 1 4 5
+M  V30 9 1 4 8 CFG=1
+M  V30 10 1 5 6
+M  V30 11 1 5 7 CFG=1
+M  V30 12 1 12 13
+M  V30 13 1 12 18 CFG=1
+M  V30 14 1 13 14
+M  V30 15 1 13 17 CFG=3
+M  V30 16 1 14 15
+M  V30 17 1 14 16 CFG=1
+M  V30 END BOND
+M  V30 BEGIN COLLECTION
+M  V30 MDLV30/STERAC2 ATOMS=(1 1)
+M  V30 MDLV30/STERAC1 ATOMS=(2 2 3)
+M  V30 MDLV30/STEABS ATOMS=(2 4 5)
+M  V30 MDLV30/STEREL1 ATOMS=(2 12 13)
+M  V30 MDLV30/STEREL2 ATOMS=(1 14)
+M  V30 END COLLECTION
+M  V30 END CTAB
+M  END
+>  <InChI>
+InChI=1S/C10H14BrCl7/c1-3(11)5(13)7(15)9(17)10(18)8(16)6(14)4(2)12/h3-10H,1-2H3/t3-,4-,5+,6-,7+,8-,9-,10+/m0/s1
+
+>  <InChI_new>
+InChI=1S/C10H14BrCl7/c1-3(11)5(13)7(15)9(17)10(18)8(16)6(14)4(2)12/h3-10H,1-2H3/t3-,4-,5+,6-,7-,8-,9+,10-/m0/s1(3,5)2(4)(6,8)3(7,9)(10)
+
+>  <Isomer>
+1EN
+
+$$$$
+
+  ACD/LABS08242216132D
+
+  0  0  0  0  0  0  0  0  0  0999 V3000
+M  V30 BEGIN CTAB
+M  V30 COUNTS 18 17 0 0 1
+M  V30 BEGIN ATOM
+M  V30 1 C 3440.9167 -681.4761 0 0
+M  V30 2 C 3369.0366 -639.976 0 0
+M  V30 3 C 3297.1567 -681.4761 0 0
+M  V30 4 C 3225.2764 -639.976 0 0
+M  V30 5 C 3153.3965 -681.4761 0 0
+M  V30 6 C 3081.5166 -639.976 0 0
+M  V30 7 Br 3153.3965 -764.476 0 0
+M  V30 8 Cl 3225.2764 -556.976 0 0
+M  V30 9 Cl 3297.1567 -764.476 0 0
+M  V30 10 Cl 3369.0366 -556.976 0 0
+M  V30 11 Cl 3440.9167 -764.476 0 0
+M  V30 12 C 3512.7971 -639.9762 0 0
+M  V30 13 C 3584.677 -681.4769 0 0
+M  V30 14 C 3656.5569 -639.9769 0 0
+M  V30 15 C 3728.437 -681.4769 0 0
+M  V30 16 Cl 3656.5569 -556.9769 0 0
+M  V30 17 Cl 3584.677 -764.4768 0 0
+M  V30 18 Cl 3512.7971 -556.9764 0 0
+M  V30 END ATOM
+M  V30 BEGIN BOND
+M  V30 1 1 1 2
+M  V30 2 1 1 11 CFG=3
+M  V30 3 1 1 12
+M  V30 4 1 2 3
+M  V30 5 1 2 10 CFG=3
+M  V30 6 1 3 4
+M  V30 7 1 3 9 CFG=3
+M  V30 8 1 4 5
+M  V30 9 1 4 8 CFG=1
+M  V30 10 1 5 6
+M  V30 11 1 5 7 CFG=1
+M  V30 12 1 12 13
+M  V30 13 1 12 18 CFG=3
+M  V30 14 1 13 14
+M  V30 15 1 13 17 CFG=1
+M  V30 16 1 14 15
+M  V30 17 1 14 16 CFG=3
+M  V30 END BOND
+M  V30 BEGIN COLLECTION
+M  V30 MDLV30/STERAC2 ATOMS=(1 1)
+M  V30 MDLV30/STERAC1 ATOMS=(2 2 3)
+M  V30 MDLV30/STEABS ATOMS=(2 4 5)
+M  V30 MDLV30/STEREL1 ATOMS=(2 12 13)
+M  V30 MDLV30/STEREL2 ATOMS=(1 14)
+M  V30 END COLLECTION
+M  V30 END CTAB
+M  END
+>  <InChI>
+InChI=1S/C10H14BrCl7/c1-3(11)5(13)7(15)9(17)10(18)8(16)6(14)4(2)12/h3-10H,1-2H3/t3-,4+,5+,6+,7+,8+,9-,10-/m0/s1
+
+>  <InChI_new>
+InChI=1S/C10H14BrCl7/c1-3(11)5(13)7(15)9(17)10(18)8(16)6(14)4(2)12/h3-10H,1-2H3/t3-,4-,5+,6-,7-,8-,9+,10-/m0/s1(3,5)2(4)(6,8)3(7,9)(10)
+
+>  <Isomer>
+1EN
+
+$$$$
+
+  ACD/LABS08242216132D
+
+  0  0  0  0  0  0  0  0  0  0999 V3000
+M  V30 BEGIN CTAB
+M  V30 COUNTS 18 17 0 0 1
+M  V30 BEGIN ATOM
+M  V30 1 C 2634.2778 -678.3174 0 0
+M  V30 2 C 2562.3979 -636.8173 0 0
+M  V30 3 C 2490.5178 -678.3174 0 0
+M  V30 4 C 2418.6377 -636.8173 0 0
+M  V30 5 C 2346.7576 -678.3174 0 0
+M  V30 6 C 2274.8774 -636.8173 0 0
+M  V30 7 Br 2346.7576 -761.3173 0 0
+M  V30 8 Cl 2418.6377 -553.8173 0 0
+M  V30 9 Cl 2490.5178 -761.3173 0 0
+M  V30 10 Cl 2562.3979 -553.8173 0 0
+M  V30 11 Cl 2634.2778 -761.3173 0 0
+M  V30 12 C 2706.1582 -636.8175 0 0
+M  V30 13 C 2778.0381 -678.3182 0 0
+M  V30 14 C 2849.918 -636.8182 0 0
+M  V30 15 C 2921.7981 -678.3182 0 0
+M  V30 16 Cl 2849.918 -553.8182 0 0
+M  V30 17 Cl 2778.0381 -761.3181 0 0
+M  V30 18 Cl 2706.1582 -553.8177 0 0
+M  V30 END ATOM
+M  V30 BEGIN BOND
+M  V30 1 1 1 2
+M  V30 2 1 1 11 CFG=1
+M  V30 3 1 1 12
+M  V30 4 1 2 3
+M  V30 5 1 2 10 CFG=3
+M  V30 6 1 3 4
+M  V30 7 1 3 9 CFG=3
+M  V30 8 1 4 5
+M  V30 9 1 4 8 CFG=1
+M  V30 10 1 5 6
+M  V30 11 1 5 7 CFG=1
+M  V30 12 1 12 13
+M  V30 13 1 12 18 CFG=3
+M  V30 14 1 13 14
+M  V30 15 1 13 17 CFG=1
+M  V30 16 1 14 15
+M  V30 17 1 14 16 CFG=3
+M  V30 END BOND
+M  V30 BEGIN COLLECTION
+M  V30 MDLV30/STERAC2 ATOMS=(1 1)
+M  V30 MDLV30/STERAC1 ATOMS=(2 2 3)
+M  V30 MDLV30/STEABS ATOMS=(2 4 5)
+M  V30 MDLV30/STEREL1 ATOMS=(2 12 13)
+M  V30 MDLV30/STEREL2 ATOMS=(1 14)
+M  V30 END COLLECTION
+M  V30 END CTAB
+M  END
+>  <InChI>
+InChI=1S/C10H14BrCl7/c1-3(11)5(13)7(15)9(17)10(18)8(16)6(14)4(2)12/h3-10H,1-2H3/t3-,4+,5+,6+,7+,8+,9-,10+/m0/s1
+
+>  <InChI_new>
+InChI=1S/C10H14BrCl7/c1-3(11)5(13)7(15)9(17)10(18)8(16)6(14)4(2)12/h3-10H,1-2H3/t3-,4-,5+,6-,7-,8-,9+,10-/m0/s1(3,5)2(4)(6,8)3(7,9)(10)
+
+>  <Isomer>
+1EN
+
+$$$$
+
+  ACD/LABS08242216132D
+
+  0  0  0  0  0  0  0  0  0  0999 V3000
+M  V30 BEGIN CTAB
+M  V30 COUNTS 18 17 0 0 1
+M  V30 BEGIN ATOM
+M  V30 1 C 1669.2778 -675.3174 0 0
+M  V30 2 C 1597.3978 -633.8173 0 0
+M  V30 3 C 1525.5178 -675.3174 0 0
+M  V30 4 C 1453.6376 -633.8173 0 0
+M  V30 5 C 1381.7576 -675.3174 0 0
+M  V30 6 C 1309.8776 -633.8173 0 0
+M  V30 7 Br 1381.7576 -758.3173 0 0
+M  V30 8 Cl 1453.6376 -550.8173 0 0
+M  V30 9 Cl 1525.5178 -758.3173 0 0
+M  V30 10 Cl 1597.3978 -550.8173 0 0
+M  V30 11 Cl 1669.2778 -758.3173 0 0
+M  V30 12 C 1741.1582 -633.8175 0 0
+M  V30 13 C 1813.0381 -675.3182 0 0
+M  V30 14 C 1884.918 -633.8182 0 0
+M  V30 15 C 1956.7981 -675.3182 0 0
+M  V30 16 Cl 1884.918 -550.8182 0 0
+M  V30 17 Cl 1813.0381 -758.3181 0 0
+M  V30 18 Cl 1741.1582 -550.8177 0 0
+M  V30 END ATOM
+M  V30 BEGIN BOND
+M  V30 1 1 1 2
+M  V30 2 1 1 11 CFG=3
+M  V30 3 1 1 12
+M  V30 4 1 2 3
+M  V30 5 1 2 10 CFG=3
+M  V30 6 1 3 4
+M  V30 7 1 3 9 CFG=3
+M  V30 8 1 4 5
+M  V30 9 1 4 8 CFG=1
+M  V30 10 1 5 6
+M  V30 11 1 5 7 CFG=1
+M  V30 12 1 12 13
+M  V30 13 1 12 18 CFG=1
+M  V30 14 1 13 14
+M  V30 15 1 13 17 CFG=3
+M  V30 16 1 14 15
+M  V30 17 1 14 16 CFG=3
+M  V30 END BOND
+M  V30 BEGIN COLLECTION
+M  V30 MDLV30/STERAC2 ATOMS=(1 1)
+M  V30 MDLV30/STERAC1 ATOMS=(2 2 3)
+M  V30 MDLV30/STEABS ATOMS=(2 4 5)
+M  V30 MDLV30/STEREL1 ATOMS=(2 12 13)
+M  V30 MDLV30/STEREL2 ATOMS=(1 14)
+M  V30 END COLLECTION
+M  V30 END CTAB
+M  END
+>  <InChI>
+InChI=1S/C10H14BrCl7/c1-3(11)5(13)7(15)9(17)10(18)8(16)6(14)4(2)12/h3-10H,1-2H3/t3-,4+,5+,6-,7+,8-,9-,10-/m0/s1
+
+>  <InChI_new>
+InChI=1S/C10H14BrCl7/c1-3(11)5(13)7(15)9(17)10(18)8(16)6(14)4(2)12/h3-10H,1-2H3/t3-,4-,5+,6-,7-,8-,9+,10-/m0/s1(3,5)2(4)(6,8)3(7,9)(10)
+
+>  <Isomer>
+1EN
+
+$$$$
+
+  ACD/LABS08242216132D
+
+  0  0  0  0  0  0  0  0  0  0999 V3000
+M  V30 BEGIN CTAB
+M  V30 COUNTS 18 17 0 0 1
+M  V30 BEGIN ATOM
+M  V30 1 C 719.8806 -405.6257 0 0
+M  V30 2 C 638.4742 -358.6256 0 0
+M  V30 3 C 557.0679 -405.6257 0 0
+M  V30 4 C 475.6614 -358.6256 0 0
+M  V30 5 C 394.255 -405.6257 0 0
+M  V30 6 C 312.8487 -358.6256 0 0
+M  V30 7 Br 394.255 -499.6256 0 0
+M  V30 8 Cl 475.6614 -264.6255 0 0
+M  V30 9 Cl 557.0679 -499.6256 0 0
+M  V30 10 Cl 638.4742 -264.6255 0 0
+M  V30 11 Cl 719.8806 -499.6256 0 0
+M  V30 12 C 801.2872 -358.6258 0 0
+M  V30 13 C 882.6934 -405.6266 0 0
+M  V30 14 C 964.0997 -358.6266 0 0
+M  V30 15 C 1045.5061 -405.6266 0 0
+M  V30 16 Cl 964.0997 -264.6266 0 0
+M  V30 17 Cl 882.6934 -499.6266 0 0
+M  V30 18 Cl 801.2872 -264.626 0 0
+M  V30 END ATOM
+M  V30 BEGIN BOND
+M  V30 1 1 1 2
+M  V30 2 1 1 11 CFG=1
+M  V30 3 1 1 12
+M  V30 4 1 2 3
+M  V30 5 1 2 10 CFG=3
+M  V30 6 1 3 4
+M  V30 7 1 3 9 CFG=3
+M  V30 8 1 4 5
+M  V30 9 1 4 8 CFG=1
+M  V30 10 1 5 6
+M  V30 11 1 5 7 CFG=1
+M  V30 12 1 12 13
+M  V30 13 1 12 18 CFG=1
+M  V30 14 1 13 14
+M  V30 15 1 13 17 CFG=3
+M  V30 16 1 14 15
+M  V30 17 1 14 16 CFG=3
+M  V30 END BOND
+M  V30 BEGIN COLLECTION
+M  V30 MDLV30/STERAC2 ATOMS=(1 1)
+M  V30 MDLV30/STERAC1 ATOMS=(2 2 3)
+M  V30 MDLV30/STEABS ATOMS=(2 4 5)
+M  V30 MDLV30/STEREL1 ATOMS=(2 12 13)
+M  V30 MDLV30/STEREL2 ATOMS=(1 14)
+M  V30 END COLLECTION
+M  V30 END CTAB
+M  END
+>  <InChI>
+InChI=1S/C10H14BrCl7/c1-3(11)5(13)7(15)9(17)10(18)8(16)6(14)4(2)12/h3-10H,1-2H3/t3-,4+,5+,6-,7+,8-,9-,10+/m0/s1
+
+>  <InChI_new>
+InChI=1S/C10H14BrCl7/c1-3(11)5(13)7(15)9(17)10(18)8(16)6(14)4(2)12/h3-10H,1-2H3/t3-,4-,5+,6-,7-,8-,9+,10-/m0/s1(3,5)2(4)(6,8)3(7,9)(10)
+
+>  <Isomer>
+1EN
+
+$$$$
+
+  ACD/LABS08242216132D
+
+  0  0  0  0  0  0  0  0  0  0999 V3000
+M  V30 BEGIN CTAB
+M  V30 COUNTS 18 17 0 0 1
+M  V30 BEGIN ATOM
+M  V30 1 C 1789.6389 -266.1587 0 0
+M  V30 2 C 1717.7589 -224.6586 0 0
+M  V30 3 C 1645.8789 -266.1587 0 0
+M  V30 4 C 1573.9987 -224.6586 0 0
+M  V30 5 C 1502.1187 -266.1587 0 0
+M  V30 6 C 1430.2386 -224.6586 0 0
+M  V30 7 Br 1502.1187 -349.1586 0 0
+M  V30 8 Cl 1573.9987 -141.6586 0 0
+M  V30 9 Cl 1645.8789 -349.1586 0 0
+M  V30 10 Cl 1717.7589 -141.6586 0 0
+M  V30 11 Cl 1789.6389 -349.1586 0 0
+M  V30 12 C 1861.5193 -224.6588 0 0
+M  V30 13 C 1933.3992 -266.1595 0 0
+M  V30 14 C 2005.2792 -224.6595 0 0
+M  V30 15 C 2077.1592 -266.1595 0 0
+M  V30 16 Cl 2005.2792 -141.6595 0 0
+M  V30 17 Cl 1933.3992 -349.1595 0 0
+M  V30 18 Cl 1861.5193 -141.659 0 0
+M  V30 END ATOM
+M  V30 BEGIN BOND
+M  V30 1 1 1 2
+M  V30 2 1 1 11 CFG=1
+M  V30 3 1 1 12
+M  V30 4 1 2 3
+M  V30 5 1 2 10 CFG=3
+M  V30 6 1 3 4
+M  V30 7 1 3 9 CFG=3
+M  V30 8 1 4 5
+M  V30 9 1 4 8 CFG=3
+M  V30 10 1 5 6
+M  V30 11 1 5 7 CFG=3
+M  V30 12 1 12 13
+M  V30 13 1 12 18 CFG=3
+M  V30 14 1 13 14
+M  V30 15 1 13 17 CFG=1
+M  V30 16 1 14 15
+M  V30 17 1 14 16 CFG=3
+M  V30 END BOND
+M  V30 BEGIN COLLECTION
+M  V30 MDLV30/STERAC2 ATOMS=(1 1)
+M  V30 MDLV30/STEABS ATOMS=(2 2 3)
+M  V30 MDLV30/STERAC1 ATOMS=(2 4 5)
+M  V30 MDLV30/STEREL2 ATOMS=(2 12 13)
+M  V30 MDLV30/STEREL1 ATOMS=(1 14)
+M  V30 END COLLECTION
+M  V30 END CTAB
+M  END
+>  <InChI>
+InChI=1S/C10H14BrCl7/c1-3(11)5(13)7(15)9(17)10(18)8(16)6(14)4(2)12/h3-10H,1-2H3/t3-,4-,5+,6-,7-,8-,9+,10-/m1/s1
+
+>  <InChI_new>
+InChI=1S/C10H14BrCl7/c1-3(11)5(13)7(15)9(17)10(18)8(16)6(14)4(2)12/h3-10H,1-2H3/t3-,4-,5+,6-,7-,8-,9+,10-/m1/s1(7,9)2(4)(6,8)3(3,5)(10)
+
+>  <Isomer>
+2EN
+
+$$$$
+
+  ACD/LABS08242216132D
+
+  0  0  0  0  0  0  0  0  0  0999 V3000
+M  V30 BEGIN CTAB
+M  V30 COUNTS 18 17 0 0 1
+M  V30 BEGIN ATOM
+M  V30 1 C 1789.6389 -266.1587 0 0
+M  V30 2 C 1717.7589 -224.6586 0 0
+M  V30 3 C 1645.8789 -266.1587 0 0
+M  V30 4 C 1573.9987 -224.6586 0 0
+M  V30 5 C 1502.1187 -266.1587 0 0
+M  V30 6 C 1430.2386 -224.6586 0 0
+M  V30 7 Br 1502.1187 -349.1586 0 0
+M  V30 8 Cl 1573.9987 -141.6586 0 0
+M  V30 9 Cl 1645.8789 -349.1586 0 0
+M  V30 10 Cl 1717.7589 -141.6586 0 0
+M  V30 11 Cl 1789.6389 -349.1586 0 0
+M  V30 12 C 1861.5193 -224.6588 0 0
+M  V30 13 C 1933.3992 -266.1595 0 0
+M  V30 14 C 2005.2792 -224.6595 0 0
+M  V30 15 C 2077.1592 -266.1595 0 0
+M  V30 16 Cl 2005.2792 -141.6595 0 0
+M  V30 17 Cl 1933.3992 -349.1595 0 0
+M  V30 18 Cl 1861.5193 -141.659 0 0
+M  V30 END ATOM
+M  V30 BEGIN BOND
+M  V30 1 1 1 2
+M  V30 2 1 1 11 CFG=1
+M  V30 3 1 1 12
+M  V30 4 1 2 3
+M  V30 5 1 2 10 CFG=3
+M  V30 6 1 3 4
+M  V30 7 1 3 9 CFG=3
+M  V30 8 1 4 5
+M  V30 9 1 4 8 CFG=3
+M  V30 10 1 5 6
+M  V30 11 1 5 7 CFG=3
+M  V30 12 1 12 13
+M  V30 13 1 12 18 CFG=3
+M  V30 14 1 13 14
+M  V30 15 1 13 17 CFG=1
+M  V30 16 1 14 15
+M  V30 17 1 14 16 CFG=3
+M  V30 END BOND
+M  V30 BEGIN COLLECTION
+M  V30 MDLV30/STERAC1 ATOMS=(1 1)
+M  V30 MDLV30/STEABS ATOMS=(2 2 3)
+M  V30 MDLV30/STERAC2 ATOMS=(2 4 5)
+M  V30 MDLV30/STEREL2 ATOMS=(2 12 13)
+M  V30 MDLV30/STEREL1 ATOMS=(1 14)
+M  V30 END COLLECTION
+M  V30 END CTAB
+M  END
+>  <InChI>
+InChI=1S/C10H14BrCl7/c1-3(11)5(13)7(15)9(17)10(18)8(16)6(14)4(2)12/h3-10H,1-2H3/t3-,4+,5+,6-,7+,8-,9-,10+/m0/s1
+
+>  <InChI_new>
+InChI=1S/C10H14BrCl7/c1-3(11)5(13)7(15)9(17)10(18)8(16)6(14)4(2)12/h3-10H,1-2H3/t3-,4-,5+,6-,7-,8-,9+,10-/m1/s1(7,9)2(4)(6,8)3(3,5)(10)
+
+>  <Isomer>
+2EN
+
+$$$$
+
+  ACD/LABS08242216132D
+
+  0  0  0  0  0  0  0  0  0  0999 V3000
+M  V30 BEGIN CTAB
+M  V30 COUNTS 18 17 0 0 1
+M  V30 BEGIN ATOM
+M  V30 1 C 1789.6389 -266.1587 0 0
+M  V30 2 C 1717.7589 -224.6586 0 0
+M  V30 3 C 1645.8789 -266.1587 0 0
+M  V30 4 C 1573.9987 -224.6586 0 0
+M  V30 5 C 1502.1187 -266.1587 0 0
+M  V30 6 C 1430.2386 -224.6586 0 0
+M  V30 7 Br 1502.1187 -349.1586 0 0
+M  V30 8 Cl 1573.9987 -141.6586 0 0
+M  V30 9 Cl 1645.8789 -349.1586 0 0
+M  V30 10 Cl 1717.7589 -141.6586 0 0
+M  V30 11 Cl 1789.6389 -349.1586 0 0
+M  V30 12 C 1861.5193 -224.6588 0 0
+M  V30 13 C 1933.3992 -266.1595 0 0
+M  V30 14 C 2005.2792 -224.6595 0 0
+M  V30 15 C 2077.1592 -266.1595 0 0
+M  V30 16 Cl 2005.2792 -141.6595 0 0
+M  V30 17 Cl 1933.3992 -349.1595 0 0
+M  V30 18 Cl 1861.5193 -141.659 0 0
+M  V30 END ATOM
+M  V30 BEGIN BOND
+M  V30 1 1 1 2
+M  V30 2 1 1 11 CFG=1
+M  V30 3 1 1 12
+M  V30 4 1 2 3
+M  V30 5 1 2 10 CFG=3
+M  V30 6 1 3 4
+M  V30 7 1 3 9 CFG=3
+M  V30 8 1 4 5
+M  V30 9 1 4 8 CFG=3
+M  V30 10 1 5 6
+M  V30 11 1 5 7 CFG=3
+M  V30 12 1 12 13
+M  V30 13 1 12 18 CFG=3
+M  V30 14 1 13 14
+M  V30 15 1 13 17 CFG=1
+M  V30 16 1 14 15
+M  V30 17 1 14 16 CFG=3
+M  V30 END BOND
+M  V30 BEGIN COLLECTION
+M  V30 MDLV30/STERAC1 ATOMS=(1 1)
+M  V30 MDLV30/STEABS ATOMS=(2 2 3)
+M  V30 MDLV30/STERAC2 ATOMS=(2 4 5)
+M  V30 MDLV30/STEREL1 ATOMS=(2 12 13)
+M  V30 MDLV30/STEREL2 ATOMS=(1 14)
+M  V30 END COLLECTION
+M  V30 END CTAB
+M  END
+>  <InChI>
+InChI=1S/C10H14BrCl7/c1-3(11)5(13)7(15)9(17)10(18)8(16)6(14)4(2)12/h3-10H,1-2H3/t3-,4+,5+,6-,7+,8-,9-,10+/m0/s1
+
+>  <InChI_new>
+InChI=1S/C10H14BrCl7/c1-3(11)5(13)7(15)9(17)10(18)8(16)6(14)4(2)12/h3-10H,1-2H3/t3-,4-,5+,6-,7-,8-,9+,10-/m1/s1(7,9)2(4)(6,8)3(3,5)(10)
+
+>  <Isomer>
+2EN
+
+$$$$
+
+  ACD/LABS08242216132D
+
+  0  0  0  0  0  0  0  0  0  0999 V3000
+M  V30 BEGIN CTAB
+M  V30 COUNTS 18 17 0 0 1
+M  V30 BEGIN ATOM
+M  V30 1 C 1789.6389 -266.1587 0 0
+M  V30 2 C 1717.7589 -224.6586 0 0
+M  V30 3 C 1645.8789 -266.1587 0 0
+M  V30 4 C 1573.9987 -224.6586 0 0
+M  V30 5 C 1502.1187 -266.1587 0 0
+M  V30 6 C 1430.2386 -224.6586 0 0
+M  V30 7 Br 1502.1187 -349.1586 0 0
+M  V30 8 Cl 1573.9987 -141.6586 0 0
+M  V30 9 Cl 1645.8789 -349.1586 0 0
+M  V30 10 Cl 1717.7589 -141.6586 0 0
+M  V30 11 Cl 1789.6389 -349.1586 0 0
+M  V30 12 C 1861.5193 -224.6588 0 0
+M  V30 13 C 1933.3992 -266.1595 0 0
+M  V30 14 C 2005.2792 -224.6595 0 0
+M  V30 15 C 2077.1592 -266.1595 0 0
+M  V30 16 Cl 2005.2792 -141.6595 0 0
+M  V30 17 Cl 1933.3992 -349.1595 0 0
+M  V30 18 Cl 1861.5193 -141.659 0 0
+M  V30 END ATOM
+M  V30 BEGIN BOND
+M  V30 1 1 1 2
+M  V30 2 1 1 11 CFG=3
+M  V30 3 1 1 12
+M  V30 4 1 2 3
+M  V30 5 1 2 10 CFG=3
+M  V30 6 1 3 4
+M  V30 7 1 3 9 CFG=3
+M  V30 8 1 4 5
+M  V30 9 1 4 8 CFG=1
+M  V30 10 1 5 6
+M  V30 11 1 5 7 CFG=1
+M  V30 12 1 12 13
+M  V30 13 1 12 18 CFG=3
+M  V30 14 1 13 14
+M  V30 15 1 13 17 CFG=1
+M  V30 16 1 14 15
+M  V30 17 1 14 16 CFG=3
+M  V30 END BOND
+M  V30 BEGIN COLLECTION
+M  V30 MDLV30/STERAC1 ATOMS=(1 1)
+M  V30 MDLV30/STEABS ATOMS=(2 2 3)
+M  V30 MDLV30/STERAC2 ATOMS=(2 4 5)
+M  V30 MDLV30/STEREL1 ATOMS=(2 12 13)
+M  V30 MDLV30/STEREL2 ATOMS=(1 14)
+M  V30 END COLLECTION
+M  V30 END CTAB
+M  END
+>  <InChI>
+InChI=1S/C10H14BrCl7/c1-3(11)5(13)7(15)9(17)10(18)8(16)6(14)4(2)12/h3-10H,1-2H3/t3-,4+,5+,6-,7+,8-,9-,10+/m0/s1
+
+>  <InChI_new>
+InChI=1S/C10H14BrCl7/c1-3(11)5(13)7(15)9(17)10(18)8(16)6(14)4(2)12/h3-10H,1-2H3/t3-,4-,5+,6-,7-,8-,9+,10-/m1/s1(7,9)2(4)(6,8)3(3,5)(10)
+
+>  <Isomer>
+2EN
+
+$$$$
+
+  ACD/LABS08242216132D
+
+  0  0  0  0  0  0  0  0  0  0999 V3000
+M  V30 BEGIN CTAB
+M  V30 COUNTS 18 17 0 0 1
+M  V30 BEGIN ATOM
+M  V30 1 C 1789.6389 -266.1587 0 0
+M  V30 2 C 1717.7589 -224.6586 0 0
+M  V30 3 C 1645.8789 -266.1587 0 0
+M  V30 4 C 1573.9987 -224.6586 0 0
+M  V30 5 C 1502.1187 -266.1587 0 0
+M  V30 6 C 1430.2386 -224.6586 0 0
+M  V30 7 Br 1502.1187 -349.1586 0 0
+M  V30 8 Cl 1573.9987 -141.6586 0 0
+M  V30 9 Cl 1645.8789 -349.1586 0 0
+M  V30 10 Cl 1717.7589 -141.6586 0 0
+M  V30 11 Cl 1789.6389 -349.1586 0 0
+M  V30 12 C 1861.5193 -224.6588 0 0
+M  V30 13 C 1933.3992 -266.1595 0 0
+M  V30 14 C 2005.2792 -224.6595 0 0
+M  V30 15 C 2077.1592 -266.1595 0 0
+M  V30 16 Cl 2005.2792 -141.6595 0 0
+M  V30 17 Cl 1933.3992 -349.1595 0 0
+M  V30 18 Cl 1861.5193 -141.659 0 0
+M  V30 END ATOM
+M  V30 BEGIN BOND
+M  V30 1 1 1 2
+M  V30 2 1 1 11 CFG=1
+M  V30 3 1 1 12
+M  V30 4 1 2 3
+M  V30 5 1 2 10 CFG=3
+M  V30 6 1 3 4
+M  V30 7 1 3 9 CFG=3
+M  V30 8 1 4 5
+M  V30 9 1 4 8 CFG=1
+M  V30 10 1 5 6
+M  V30 11 1 5 7 CFG=1
+M  V30 12 1 12 13
+M  V30 13 1 12 18 CFG=1
+M  V30 14 1 13 14
+M  V30 15 1 13 17 CFG=3
+M  V30 16 1 14 15
+M  V30 17 1 14 16 CFG=3
+M  V30 END BOND
+M  V30 BEGIN COLLECTION
+M  V30 MDLV30/STERAC1 ATOMS=(1 1)
+M  V30 MDLV30/STEABS ATOMS=(2 2 3)
+M  V30 MDLV30/STERAC2 ATOMS=(2 4 5)
+M  V30 MDLV30/STEREL1 ATOMS=(2 12 13)
+M  V30 MDLV30/STEREL2 ATOMS=(1 14)
+M  V30 END COLLECTION
+M  V30 END CTAB
+M  END
+>  <InChI>
+InChI=1S/C10H14BrCl7/c1-3(11)5(13)7(15)9(17)10(18)8(16)6(14)4(2)12/h3-10H,1-2H3/t3-,4+,5+,6-,7+,8-,9-,10+/m0/s1
+
+>  <InChI_new>
+InChI=1S/C10H14BrCl7/c1-3(11)5(13)7(15)9(17)10(18)8(16)6(14)4(2)12/h3-10H,1-2H3/t3-,4-,5+,6-,7-,8-,9+,10-/m1/s1(7,9)2(4)(6,8)3(3,5)(10)
+
+>  <Isomer>
+2EN
+
+$$$$
+
+  ACD/LABS08242216132D
+
+  0  0  0  0  0  0  0  0  0  0999 V3000
+M  V30 BEGIN CTAB
+M  V30 COUNTS 8 8 0 0 1
+M  V30 BEGIN ATOM
+M  V30 1 C 858.7786 -570.2803 0 0
+M  V30 2 C 907.3196 -535.0132 0 0
+M  V30 3 C 877.3196 -627.3436 0 0
+M  V30 4 O 801.7153 -551.7392 0 0
+M  V30 5 O 907.3197 -475.0132 0 0
+M  V30 6 C 955.8607 -570.2803 0 0
+M  V30 7 Cl 1012.9241 -551.7394 0 0
+M  V30 8 C 937.3196 -627.3438 0 0
+M  V30 END ATOM
+M  V30 BEGIN BOND
+M  V30 1 1 1 2
+M  V30 2 1 1 3
+M  V30 3 1 1 4 CFG=1
+M  V30 4 1 2 5 CFG=1
+M  V30 5 1 2 6
+M  V30 6 1 3 8
+M  V30 7 1 6 7 CFG=1
+M  V30 8 1 6 8
+M  V30 END BOND
+M  V30 BEGIN COLLECTION
+M  V30 MDLV30/STEREL1 ATOMS=(3 1 2 6)
+M  V30 END COLLECTION
+M  V30 END CTAB
+M  END
+>  <InChI>
+InChI=1S/C5H9ClO2/c6-3-1-2-4(7)5(3)8/h3-5,7-8H,1-2H2/t3-,4+,5-/m0/s1
+
+>  <InChI_new>
+InChI=1/C5H9ClO2/c6-3-1-2-4(7)5(3)8/h3-5,7-8H,1-2H2/t3-,4+,5-/m0/s2
+
+>  <Isomer>
+3EN
+
+$$$$
+
+  ACD/LABS08242216132D
+
+  0  0  0  0  0  0  0  0  0  0999 V3000
+M  V30 BEGIN CTAB
+M  V30 COUNTS 8 8 0 0 1
+M  V30 BEGIN ATOM
+M  V30 1 C 413.74 -573.2996 0 0
+M  V30 2 C 462.2811 -538.0325 0 0
+M  V30 3 C 432.2809 -630.3629 0 0
+M  V30 4 O 356.6766 -554.7585 0 0
+M  V30 5 O 462.2811 -478.0325 0 0
+M  V30 6 C 510.822 -573.2996 0 0
+M  V30 7 Cl 567.8854 -554.7587 0 0
+M  V30 8 C 492.281 -630.363 0 0
+M  V30 END ATOM
+M  V30 BEGIN BOND
+M  V30 1 1 1 2
+M  V30 2 1 1 3
+M  V30 3 1 1 4 CFG=3
+M  V30 4 1 2 5 CFG=3
+M  V30 5 1 2 6
+M  V30 6 1 3 8
+M  V30 7 1 6 7 CFG=3
+M  V30 8 1 6 8
+M  V30 END BOND
+M  V30 BEGIN COLLECTION
+M  V30 MDLV30/STEREL1 ATOMS=(3 1 2 6)
+M  V30 END COLLECTION
+M  V30 END CTAB
+M  END
+>  <InChI>
+InChI=1/C5H9ClO2/c6-3-1-2-4(7)5(3)8/h3-5,7-8H,1-2H2/t3-,4+,5-/m1/s1
+
+>  <InChI_new>
+InChI=1/C5H9ClO2/c6-3-1-2-4(7)5(3)8/h3-5,7-8H,1-2H2/t3-,4+,5-/m0/s2
+
+>  <Isomer>
+3EN
+
+$$$$
+
+  ACD/LABS08242216132D
+
+  0  0  0  0  0  0  0  0  0  0999 V3000
+M  V30 BEGIN CTAB
+M  V30 COUNTS 8 8 0 0 1
+M  V30 BEGIN ATOM
+M  V30 1 C 1839.8173 -572.261 0 0
+M  V30 2 C 1888.3582 -536.9939 0 0
+M  V30 3 C 1858.3582 -629.3243 0 0
+M  V30 4 O 1782.7539 -553.7199 0 0
+M  V30 5 O 1888.3583 -476.9939 0 0
+M  V30 6 C 1936.8992 -572.261 0 0
+M  V30 7 Cl 1993.9626 -553.7202 0 0
+M  V30 8 C 1918.358 -629.3245 0 0
+M  V30 END ATOM
+M  V30 BEGIN BOND
+M  V30 1 1 1 2
+M  V30 2 1 1 3
+M  V30 3 1 1 4 CFG=1
+M  V30 4 1 2 5 CFG=1
+M  V30 5 1 2 6
+M  V30 6 1 3 8
+M  V30 7 1 6 7 CFG=1
+M  V30 8 1 6 8
+M  V30 END BOND
+M  V30 BEGIN COLLECTION
+M  V30 MDLV30/STERAC1 ATOMS=(3 1 2 6)
+M  V30 END COLLECTION
+M  V30 END CTAB
+M  END
+>  <InChI>
+InChI=1S/C5H9ClO2/c6-3-1-2-4(7)5(3)8/h3-5,7-8H,1-2H2/t3-,4+,5-/m0/s1
+
+>  <InChI_new>
+InChI=1/C5H9ClO2/c6-3-1-2-4(7)5(3)8/h3-5,7-8H,1-2H2/t3-,4+,5-/m0/s3
+
+>  <Isomer>
+4EN
+
+$$$$
+
+  ACD/LABS08242216132D
+
+  0  0  0  0  0  0  0  0  0  0999 V3000
+M  V30 BEGIN CTAB
+M  V30 COUNTS 8 8 0 0 1
+M  V30 BEGIN ATOM
+M  V30 1 C 1394.7787 -575.2803 0 0
+M  V30 2 C 1443.3196 -540.0132 0 0
+M  V30 3 C 1413.3196 -632.3436 0 0
+M  V30 4 O 1337.7153 -556.7392 0 0
+M  V30 5 O 1443.3197 -480.0132 0 0
+M  V30 6 C 1491.8606 -575.2803 0 0
+M  V30 7 Cl 1548.9241 -556.7394 0 0
+M  V30 8 C 1473.3195 -632.3438 0 0
+M  V30 END ATOM
+M  V30 BEGIN BOND
+M  V30 1 1 1 2
+M  V30 2 1 1 3
+M  V30 3 1 1 4 CFG=3
+M  V30 4 1 2 5 CFG=3
+M  V30 5 1 2 6
+M  V30 6 1 3 8
+M  V30 7 1 6 7 CFG=3
+M  V30 8 1 6 8
+M  V30 END BOND
+M  V30 BEGIN COLLECTION
+M  V30 MDLV30/STERAC1 ATOMS=(3 1 2 6)
+M  V30 END COLLECTION
+M  V30 END CTAB
+M  END
+>  <InChI>
+InChI=1S/C5H9ClO2/c6-3-1-2-4(7)5(3)8/h3-5,7-8H,1-2H2/t3-,4+,5-/m1/s1
+
+>  <InChI_new>
+InChI=1/C5H9ClO2/c6-3-1-2-4(7)5(3)8/h3-5,7-8H,1-2H2/t3-,4+,5-/m0/s3
+
+>  <Isomer>
+4EN
+
+$$$$
+
+  ACD/LABS08242216132D
+
+  0  0  0  0  0  0  0  0  0  0  0 V3000
+M  V30 BEGIN CTAB
+M  V30 COUNTS 11 10 0 0 0
+M  V30 BEGIN ATOM
+M  V30 1 C 5.15734 -5.49189 0.0 0
+M  V30 2 C 6.02876 -5.00137 0.0 0 CFG=2
+M  V30 3 C 6.88929 -5.51079 0.0 0
+M  V30 4 C 7.76071 -5.02026 0.0 0 CFG=2
+M  V30 5 C 8.62123 -5.52968 0.0 0
+M  V30 6 C 9.49266 -5.03916 0.0 0 CFG=2
+M  V30 7 C 10.3532 -5.54857 0.0 0
+M  V30 8 Cl 6.03968 -4.00143 0.0 0
+M  V30 9 Br 7.77162 -4.02032 0.0 0
+M  V30 10 O 9.50357 -4.03922 0.0 0
+M  V30 11 C 4.29682 -4.98247 0.0 0
+M  V30 END ATOM
+M  V30 BEGIN BOND
+M  V30 1 1 1 2
+M  V30 2 1 1 11
+M  V30 3 1 2 3
+M  V30 4 1 2 8 CFG=1
+M  V30 5 1 3 4
+M  V30 6 1 4 5
+M  V30 7 1 4 9 CFG=1
+M  V30 8 1 5 6
+M  V30 9 1 6 7
+M  V30 10 1 6 10 CFG=1
+M  V30 END BOND
+M  V30 BEGIN COLLECTION
+M  V30 MDLV30/STEABS ATOMS=(3 2 4 6)
+M  V30 END COLLECTION
+M  V30 END CTAB
+M  END
+>  <InChI>
+InChI=1S/C7H14BrClO/c1-5(9)3-7(8)4-6(2)10/h5-7,10H,3-4H2,1-2H3/t5-,6+,7-/m1/s1
+
+>  <InChI_new>
+InChI=1S/C7H14BrClO/c1-5(9)3-7(8)4-6(2)10/h5-7,10H,3-4H2,1-2H3/t5-,6+,7-/m1/s1
+
+>  <Isomer>
+5EN
+
+$$$$
+
+  ACD/LABS08242216132D
+
+  0  0  0  0  0  0  0  0  0  0999 V3000
+M  V30 BEGIN CTAB
+M  V30 COUNTS 10 9 0 0 1
+M  V30 BEGIN ATOM
+M  V30 1 C 250 -700 0 0
+M  V30 2 C 302.2857 -670.5686 0 0
+M  V30 3 C 353.9169 -701.1337 0 0
+M  V30 4 C 406.2026 -671.7023 0 0
+M  V30 5 C 457.8337 -702.2673 0 0
+M  V30 6 C 510.1194 -672.8359 0 0
+M  V30 7 C 561.7506 -703.4009 0 0
+M  V30 8 Cl 302.9404 -610.5721 0 0
+M  V30 9 Br 406.8572 -611.7058 0 0
+M  V30 10 O 510.7741 -612.8395 0 0
+M  V30 END ATOM
+M  V30 BEGIN BOND
+M  V30 1 1 1 2
+M  V30 2 1 2 3
+M  V30 3 1 2 8 CFG=1
+M  V30 4 1 3 4
+M  V30 5 1 4 5
+M  V30 6 1 4 9 CFG=1
+M  V30 7 1 5 6
+M  V30 8 1 6 7
+M  V30 9 1 6 10 CFG=3
+M  V30 END BOND
+M  V30 BEGIN COLLECTION
+M  V30 MDLV30/STEABS ATOMS=(1 2)
+M  V30 MDLV30/STEREL1 ATOMS=(1 4)
+M  V30 MDLV30/STERAC1 ATOMS=(1 6)
+M  V30 END COLLECTION
+M  V30 END CTAB
+M  END
+>  <InChI>
+InChI=1S/C7H14BrClO/c1-5(9)3-7(8)4-6(2)10/h5-7,10H,3-4H2,1-2H3/t5-,6-,7-/m1/s1
+
+>  <InChI_new>
+InChI=1S/C7H14BrClO/c1-5(9)3-7(8)4-6(2)10/h5-7,10H,3-4H2,1-2H3/t5-,6-,7-/m1/s1(5)2(7)3(6)
+
+>  <Isomer>
+6EN
+
+$$$$
+
+  ACD/LABS08242216132D
+
+  0  0  0  0  0  0  0  0  0  0999 V3000
+M  V30 BEGIN CTAB
+M  V30 COUNTS 10 9 0 0 1
+M  V30 BEGIN ATOM
+M  V30 1 C 250 -700 0 0
+M  V30 2 C 302.2857 -670.5686 0 0
+M  V30 3 C 353.9169 -701.1337 0 0
+M  V30 4 C 406.2026 -671.7023 0 0
+M  V30 5 C 457.8337 -702.2673 0 0
+M  V30 6 C 510.1194 -672.8359 0 0
+M  V30 7 C 561.7506 -703.4009 0 0
+M  V30 8 Cl 302.9404 -610.5721 0 0
+M  V30 9 Br 406.8572 -611.7058 0 0
+M  V30 10 O 510.7741 -612.8395 0 0
+M  V30 END ATOM
+M  V30 BEGIN BOND
+M  V30 1 1 1 2
+M  V30 2 1 2 3
+M  V30 3 1 2 8 CFG=1
+M  V30 4 1 3 4
+M  V30 5 1 4 5
+M  V30 6 1 4 9 CFG=3
+M  V30 7 1 5 6
+M  V30 8 1 6 7
+M  V30 9 1 6 10 CFG=3
+M  V30 END BOND
+M  V30 BEGIN COLLECTION
+M  V30 MDLV30/STEABS ATOMS=(1 2)
+M  V30 MDLV30/STEREL1 ATOMS=(1 4)
+M  V30 MDLV30/STERAC1 ATOMS=(1 6)
+M  V30 END COLLECTION
+M  V30 END CTAB
+M  END
+>  <InChI>
+InChI=1S/C7H14BrClO/c1-5(9)3-7(8)4-6(2)10/h5-7,10H,3-4H2,1-2H3/t5-,6-,7+/m1/s1
+
+>  <InChI_new>
+InChI=1S/C7H14BrClO/c1-5(9)3-7(8)4-6(2)10/h5-7,10H,3-4H2,1-2H3/t5-,6-,7-/m1/s1(5)2(7)3(6)
+
+>  <Isomer>
+6EN
+
+$$$$
+
+  ACD/LABS08242216132D
+
+  0  0  0  0  0  0  0  0  0  0999 V3000
+M  V30 BEGIN CTAB
+M  V30 COUNTS 10 9 0 0 1
+M  V30 BEGIN ATOM
+M  V30 1 C 250 -700 0 0
+M  V30 2 C 302.2857 -670.5686 0 0
+M  V30 3 C 353.9169 -701.1337 0 0
+M  V30 4 C 406.2026 -671.7023 0 0
+M  V30 5 C 457.8337 -702.2673 0 0
+M  V30 6 C 510.1194 -672.8359 0 0
+M  V30 7 C 561.7506 -703.4009 0 0
+M  V30 8 Cl 302.9404 -610.5721 0 0
+M  V30 9 Br 406.8572 -611.7058 0 0
+M  V30 10 O 510.7741 -612.8395 0 0
+M  V30 END ATOM
+M  V30 BEGIN BOND
+M  V30 1 1 1 2
+M  V30 2 1 2 3
+M  V30 3 1 2 8 CFG=1
+M  V30 4 1 3 4
+M  V30 5 1 4 5
+M  V30 6 1 4 9 CFG=3
+M  V30 7 1 5 6
+M  V30 8 1 6 7
+M  V30 9 1 6 10 CFG=1
+M  V30 END BOND
+M  V30 BEGIN COLLECTION
+M  V30 MDLV30/STEABS ATOMS=(1 2)
+M  V30 MDLV30/STEREL1 ATOMS=(1 4)
+M  V30 MDLV30/STERAC1 ATOMS=(1 6)
+M  V30 END COLLECTION
+M  V30 END CTAB
+M  END
+>  <InChI>
+InChI=1S/C7H14BrClO/c1-5(9)3-7(8)4-6(2)10/h5-7,10H,3-4H2,1-2H3/t5-,6+,7+/m1/s1
+
+>  <InChI_new>
+InChI=1S/C7H14BrClO/c1-5(9)3-7(8)4-6(2)10/h5-7,10H,3-4H2,1-2H3/t5-,6-,7-/m1/s1(5)2(7)3(6)
+
+>  <Isomer>
+6EN
+
+$$$$
+
+  ACD/LABS08242216132D
+
+  0  0  0  0  0  0  0  0  0  0999 V3000
+M  V30 BEGIN CTAB
+M  V30 COUNTS 10 9 0 0 1
+M  V30 BEGIN ATOM
+M  V30 1 C 250 -700 0 0
+M  V30 2 C 302.2857 -670.5686 0 0
+M  V30 3 C 353.9169 -701.1337 0 0
+M  V30 4 C 406.2026 -671.7023 0 0
+M  V30 5 C 457.8337 -702.2673 0 0
+M  V30 6 C 510.1194 -672.8359 0 0
+M  V30 7 C 561.7506 -703.4009 0 0
+M  V30 8 Cl 302.9404 -610.5721 0 0
+M  V30 9 Br 406.8572 -611.7058 0 0
+M  V30 10 O 510.7741 -612.8395 0 0
+M  V30 END ATOM
+M  V30 BEGIN BOND
+M  V30 1 1 1 2
+M  V30 2 1 2 3
+M  V30 3 1 2 8 CFG=1
+M  V30 4 1 3 4
+M  V30 5 1 4 5
+M  V30 6 1 4 9 CFG=1
+M  V30 7 1 5 6
+M  V30 8 1 6 7
+M  V30 9 1 6 10 CFG=1
+M  V30 END BOND
+M  V30 BEGIN COLLECTION
+M  V30 MDLV30/STEABS ATOMS=(1 2)
+M  V30 MDLV30/STEREL1 ATOMS=(1 4)
+M  V30 MDLV30/STERAC1 ATOMS=(1 6)
+M  V30 END COLLECTION
+M  V30 END CTAB
+M  END
+>  <InChI>
+InChI=1S/C7H14BrClO/c1-5(9)3-7(8)4-6(2)10/h5-7,10H,3-4H2,1-2H3/t5-,6+,7-/m1/s1
+
+>  <InChI_new>
+InChI=1S/C7H14BrClO/c1-5(9)3-7(8)4-6(2)10/h5-7,10H,3-4H2,1-2H3/t5-,6-,7-/m1/s1(5)2(7)3(6)
+
+>  <Isomer>
+6EN
+
+$$$$
+
+  ACD/LABS08242216132D
+
+  0  0  0  0  0  0  0  0  0  0  0 V3000
+M  V30 BEGIN CTAB
+M  V30 COUNTS 11 10 0 0 0
+M  V30 BEGIN ATOM
+M  V30 1 C 3.40734 -5.94189 0.0 0
+M  V30 2 C 4.27876 -5.45137 0.0 0 CFG=2
+M  V30 3 C 5.13929 -5.96079 0.0 0
+M  V30 4 C 6.01071 -5.47026 0.0 0 CFG=2
+M  V30 5 C 6.87123 -5.97968 0.0 0
+M  V30 6 C 7.74266 -5.48916 0.0 0 CFG=2
+M  V30 7 C 8.60318 -5.99857 0.0 0
+M  V30 8 Cl 4.28968 -4.45143 0.0 0
+M  V30 9 Br 6.02162 -4.47032 0.0 0
+M  V30 10 O 7.75357 -4.48922 0.0 0
+M  V30 11 C 2.54682 -5.43247 0.0 0
+M  V30 END ATOM
+M  V30 BEGIN BOND
+M  V30 1 1 1 2
+M  V30 2 1 1 11
+M  V30 3 1 2 3
+M  V30 4 1 2 8 CFG=1
+M  V30 5 1 3 4
+M  V30 6 1 4 5
+M  V30 7 1 4 9 CFG=1
+M  V30 8 1 5 6
+M  V30 9 1 6 7
+M  V30 10 1 6 10 CFG=1
+M  V30 END BOND
+M  V30 BEGIN COLLECTION
+M  V30 MDLV30/STEABS ATOMS=(3 2 4 6)
+M  V30 END COLLECTION
+M  V30 END CTAB
+M  END
+>  <InChI>
+InChI=1S/C8H16BrClO/c1-3-8(10)5-7(9)4-6(2)11/h6-8,11H,3-5H2,1-2H3/t6-,7-,8+/m0/s1
+
+>  <InChI_new>
+InChI=1S/C8H16BrClO/c1-3-8(10)5-7(9)4-6(2)11/h6-8,11H,3-5H2,1-2H3/t6-,7-,8+/m0/s1
+
+>  <Isomer>
+7EN
+
+$$$$
+
+  ACD/LABS08242216132D
+
+  0  0  0  0  0  0  0  0  0  0999 V3000
+M  V30 BEGIN CTAB
+M  V30 COUNTS 11 10 0 0 1
+M  V30 BEGIN ATOM
+M  V30 1 C 1012 -1609 0 0
+M  V30 2 C 1064.2856 -1579.5686 0 0
+M  V30 3 C 1115.9169 -1610.1337 0 0
+M  V30 4 C 1168.2026 -1580.7023 0 0
+M  V30 5 C 1219.8337 -1611.2673 0 0
+M  V30 6 C 1272.1194 -1581.8359 0 0
+M  V30 7 C 1323.7506 -1612.4009 0 0
+M  V30 8 Cl 1064.9404 -1519.5721 0 0
+M  V30 9 Br 1168.8572 -1520.7058 0 0
+M  V30 10 O 1272.7742 -1521.8395 0 0
+M  V30 11 C 960.3689 -1578.4348 0 0
+M  V30 END ATOM
+M  V30 BEGIN BOND
+M  V30 1 1 1 2
+M  V30 2 1 1 11
+M  V30 3 1 2 3
+M  V30 4 1 2 8 CFG=3
+M  V30 5 1 3 4
+M  V30 6 1 4 5
+M  V30 7 1 4 9 CFG=3
+M  V30 8 1 5 6
+M  V30 9 1 6 7
+M  V30 10 1 6 10 CFG=3
+M  V30 END BOND
+M  V30 BEGIN COLLECTION
+M  V30 MDLV30/STEREL1 ATOMS=(2 2 4)
+M  V30 MDLV30/STERAC1 ATOMS=(1 6)
+M  V30 END COLLECTION
+M  V30 END CTAB
+M  END
+>  <InChI>
+InChI=1S/C8H16BrClO/c1-3-8(10)5-7(9)4-6(2)11/h6-8,11H,3-5H2,1-2H3/t6-,7-,8+/m1/s1
+
+>  <InChI_new>
+InChI=1S/C8H16BrClO/c1-3-8(10)5-7(9)4-6(2)11/h6-8,11H,3-5H2,1-2H3/t6-,7-,8+/m0/s2(7,8)3(6)
+
+>  <Isomer>
+8EN
+
+$$$$
+
+  ACD/LABS08242216132D
+
+  0  0  0  0  0  0  0  0  0  0999 V3000
+M  V30 BEGIN CTAB
+M  V30 COUNTS 11 10 0 0 1
+M  V30 BEGIN ATOM
+M  V30 1 C 1012 -1609 0 0
+M  V30 2 C 1064.2856 -1579.5686 0 0
+M  V30 3 C 1115.9169 -1610.1337 0 0
+M  V30 4 C 1168.2026 -1580.7023 0 0
+M  V30 5 C 1219.8337 -1611.2673 0 0
+M  V30 6 C 1272.1194 -1581.8359 0 0
+M  V30 7 C 1323.7506 -1612.4009 0 0
+M  V30 8 Cl 1064.9404 -1519.5721 0 0
+M  V30 9 Br 1168.8572 -1520.7058 0 0
+M  V30 10 O 1272.7742 -1521.8395 0 0
+M  V30 11 C 960.3689 -1578.4348 0 0
+M  V30 END ATOM
+M  V30 BEGIN BOND
+M  V30 1 1 1 2
+M  V30 2 1 1 11
+M  V30 3 1 2 3
+M  V30 4 1 2 8 CFG=1
+M  V30 5 1 3 4
+M  V30 6 1 4 5
+M  V30 7 1 4 9 CFG=1
+M  V30 8 1 5 6
+M  V30 9 1 6 7
+M  V30 10 1 6 10 CFG=3
+M  V30 END BOND
+M  V30 BEGIN COLLECTION
+M  V30 MDLV30/STEREL1 ATOMS=(2 2 4)
+M  V30 MDLV30/STERAC1 ATOMS=(1 6)
+M  V30 END COLLECTION
+M  V30 END CTAB
+M  END
+>  <InChI>
+InChI=1S/C8H16BrClO/c1-3-8(10)5-7(9)4-6(2)11/h6-8,11H,3-5H2,1-2H3/t6-,7+,8-/m1/s1
+
+>  <InChI_new>
+InChI=1S/C8H16BrClO/c1-3-8(10)5-7(9)4-6(2)11/h6-8,11H,3-5H2,1-2H3/t6-,7-,8+/m0/s2(7,8)3(6)
+
+>  <Isomer>
+8EN
+
+$$$$
+
+  ACD/LABS08242216132D
+
+  0  0  0  0  0  0  0  0  0  0999 V3000
+M  V30 BEGIN CTAB
+M  V30 COUNTS 11 10 0 0 1
+M  V30 BEGIN ATOM
+M  V30 1 C 1012 -1609 0 0
+M  V30 2 C 1064.2856 -1579.5686 0 0
+M  V30 3 C 1115.9169 -1610.1337 0 0
+M  V30 4 C 1168.2026 -1580.7023 0 0
+M  V30 5 C 1219.8337 -1611.2673 0 0
+M  V30 6 C 1272.1194 -1581.8359 0 0
+M  V30 7 C 1323.7506 -1612.4009 0 0
+M  V30 8 Cl 1064.9404 -1519.5721 0 0
+M  V30 9 Br 1168.8572 -1520.7058 0 0
+M  V30 10 O 1272.7742 -1521.8395 0 0
+M  V30 11 C 960.3689 -1578.4348 0 0
+M  V30 END ATOM
+M  V30 BEGIN BOND
+M  V30 1 1 1 2
+M  V30 2 1 1 11
+M  V30 3 1 2 3
+M  V30 4 1 2 8 CFG=3
+M  V30 5 1 3 4
+M  V30 6 1 4 5
+M  V30 7 1 4 9 CFG=3
+M  V30 8 1 5 6
+M  V30 9 1 6 7
+M  V30 10 1 6 10 CFG=1
+M  V30 END BOND
+M  V30 BEGIN COLLECTION
+M  V30 MDLV30/STEREL1 ATOMS=(2 2 4)
+M  V30 MDLV30/STERAC1 ATOMS=(1 6)
+M  V30 END COLLECTION
+M  V30 END CTAB
+M  END
+>  <InChI>
+InChI=1S/C8H16BrClO/c1-3-8(10)5-7(9)4-6(2)11/h6-8,11H,3-5H2,1-2H3/t6-,7+,8-/m0/s1
+
+>  <InChI_new>
+InChI=1S/C8H16BrClO/c1-3-8(10)5-7(9)4-6(2)11/h6-8,11H,3-5H2,1-2H3/t6-,7-,8+/m0/s2(7,8)3(6)
+
+>  <Isomer>
+8EN
+
+$$$$
+
+  ACD/LABS08242216132D
+
+  0  0  0  0  0  0  0  0  0  0999 V3000
+M  V30 BEGIN CTAB
+M  V30 COUNTS 11 10 0 0 1
+M  V30 BEGIN ATOM
+M  V30 1 C 1016 -1151 0 0
+M  V30 2 C 1068.2856 -1121.5686 0 0
+M  V30 3 C 1119.9169 -1152.1337 0 0
+M  V30 4 C 1172.2026 -1122.7023 0 0
+M  V30 5 C 1223.8337 -1153.2673 0 0
+M  V30 6 C 1276.1194 -1123.8359 0 0
+M  V30 7 C 1327.7506 -1154.4009 0 0
+M  V30 8 Cl 1068.9404 -1061.5721 0 0
+M  V30 9 Br 1172.8572 -1062.7058 0 0
+M  V30 10 O 1276.7742 -1063.8395 0 0
+M  V30 11 C 964.3689 -1120.4348 0 0
+M  V30 END ATOM
+M  V30 BEGIN BOND
+M  V30 1 1 1 2
+M  V30 2 1 1 11
+M  V30 3 1 2 3
+M  V30 4 1 2 8 CFG=1
+M  V30 5 1 3 4
+M  V30 6 1 4 5
+M  V30 7 1 4 9 CFG=1
+M  V30 8 1 5 6
+M  V30 9 1 6 7
+M  V30 10 1 6 10 CFG=1
+M  V30 END BOND
+M  V30 BEGIN COLLECTION
+M  V30 MDLV30/STEREL1 ATOMS=(2 2 4)
+M  V30 MDLV30/STERAC1 ATOMS=(1 6)
+M  V30 END COLLECTION
+M  V30 END CTAB
+M  END
+>  <InChI>
+InChI=1S/C8H16BrClO/c1-3-8(10)5-7(9)4-6(2)11/h6-8,11H,3-5H2,1-2H3/t6-,7-,8+/m0/s1
+
+>  <InChI_new>
+InChI=1S/C8H16BrClO/c1-3-8(10)5-7(9)4-6(2)11/h6-8,11H,3-5H2,1-2H3/t6-,7-,8+/m0/s2(7,8)3(6)
+
+>  <Isomer>
+8EN
+
+$$$$
diff --git a/INCHI-1-TEST/tests/test_unit/test_enhancedStereo.cpp b/INCHI-1-TEST/tests/test_unit/test_enhancedStereo.cpp
new file mode 100644
index 00000000..0a771802
--- /dev/null
+++ b/INCHI-1-TEST/tests/test_unit/test_enhancedStereo.cpp
@@ -0,0 +1,1229 @@
+#include <gtest/gtest.h>
+#include <fstream>
+
+extern "C"
+{
+#include "../../../INCHI-1-SRC/INCHI_BASE/src/inchi_api.h"
+#include "../../../INCHI-1-SRC/INCHI_BASE/src/mode.h"
+}
+
+TEST(test_enhancedStereo, test_EnhancedStereochemistry_molfile_v2)
+{
+    const char *molblock =
+        "test_mol_2																  \n"
+        "  Ketcher  1302610202D 1   1.00000     0.00000     0                     \n"
+        "                                                                         \n"
+        " 13 12  0  0  0  0  0  0  0  0999 V2000                                  \n"
+        "    2.9420   -4.1000    0.0000 C   0  0  0  0  0  0  0  0  0  0  0  0    \n"
+        "    3.8080   -3.6000    0.0000 C   0  0  0  0  0  0  0  0  0  0  0  0    \n"
+        "    4.6740   -4.1000    0.0000 C   0  0  0  0  0  0  0  0  0  0  0  0    \n"
+        "    5.5401   -3.6000    0.0000 C   0  0  0  0  0  0  0  0  0  0  0  0    \n"
+        "    6.4061   -4.1000    0.0000 C   0  0  0  0  0  0  0  0  0  0  0  0    \n"
+        "    7.2721   -3.6000    0.0000 C   0  0  0  0  0  0  0  0  0  0  0  0    \n"
+        "    8.1381   -4.1000    0.0000 C   0  0  0  0  0  0  0  0  0  0  0  0    \n"
+        "    6.4061   -5.1000    0.0000 C   0  0  0  0  0  0  0  0  0  0  0  0    \n"
+        "    5.5401   -2.6000    0.0000 C   0  0  0  0  0  0  0  0  0  0  0  0    \n"
+        "    5.5401   -5.6000    0.0000 C   0  0  0  0  0  0  0  0  0  0  0  0    \n"
+        "    5.5401   -6.6000    0.0000 C   0  0  0  0  0  0  0  0  0  0  0  0    \n"
+        "    6.4061   -2.1000    0.0000 C   0  0  0  0  0  0  0  0  0  0  0  0    \n"
+        "    6.4061   -1.1000    0.0000 C   0  0  0  0  0  0  0  0  0  0  0  0    \n"
+        "  1  2  1  0     0  0                                                    \n"
+        "  2  3  1  0     0  0                                                    \n"
+        "  3  4  1  0     0  0                                                    \n"
+        "  4  5  1  0     0  0                                                    \n"
+        "  5  6  1  0     0  0                                                    \n"
+        "  6  7  1  0     0  0                                                    \n"
+        "  5  8  1  0     0  0                                                    \n"
+        "  4  9  1  0     0  0                                                    \n"
+        "  8 10  1  0     0  0                                                    \n"
+        " 10 11  1  0     0  0                                                    \n"
+        "  9 12  1  0     0  0                                                    \n"
+        " 12 13  1  0     0  0                                                    \n"
+        "M  END                                                                   \n";
+
+    char options[] = "-EnhancedStereochemistry";
+    inchi_Output output;
+    inchi_Output *poutput = &output;
+    const char expected_inchi[] = "InChI=1B/C13H28/c1-5-9-12(8-4)13(10-6-2)11-7-3/h12-13H,5-11H2,1-4H3";
+
+    EXPECT_EQ(MakeINCHIFromMolfileText(molblock, options, poutput), 1);
+    EXPECT_STREQ(poutput->szInChI, expected_inchi);
+
+    FreeINCHI(poutput);
+}
+
+TEST(test_enhancedStereo, test_EnhancedStereochemistry_1)
+{
+    const char *molblock =
+        "enhanc_stereo1									   \n"
+        "  ACD/LABS08242216132D                            \n"
+        "												   \n"
+        "  0  0  0  0  0  0  0  0  0  0999 V3000           \n"
+        "M  V30 BEGIN CTAB                                 \n"
+        "M  V30 COUNTS 18 17 0 0 1                         \n"
+        "M  V30 BEGIN ATOM                                 \n"
+        "M  V30 1 C 3424.1946 -1936.7935 0 0               \n"
+        "M  V30 2 C 3352.3145 -1895.2935 0 0               \n"
+        "M  V30 3 C 3280.4346 -1936.7935 0 0               \n"
+        "M  V30 4 C 3208.5542 -1895.2935 0 0               \n"
+        "M  V30 5 C 3136.6743 -1936.7935 0 0               \n"
+        "M  V30 6 C 3064.7944 -1895.2935 0 0               \n"
+        "M  V30 7 Br 3136.6743 -2019.7935 0 0              \n"
+        "M  V30 8 Cl 3208.5542 -1812.2935 0 0              \n"
+        "M  V30 9 Cl 3280.4346 -2019.7935 0 0              \n"
+        "M  V30 10 Cl 3352.3145 -1812.2935 0 0             \n"
+        "M  V30 11 Cl 3424.1946 -2019.7935 0 0             \n"
+        "M  V30 12 C 3496.075 -1895.2935 0 0               \n"
+        "M  V30 13 C 3567.9548 -1936.7942 0 0              \n"
+        "M  V30 14 C 3639.835 -1895.2944 0 0               \n"
+        "M  V30 15 C 3711.7148 -1936.7942 0 0              \n"
+        "M  V30 16 Cl 3639.835 -1812.2944 0 0              \n"
+        "M  V30 17 Cl 3567.9548 -2019.7942 0 0             \n"
+        "M  V30 18 Cl 3496.075 -1812.2937 0 0              \n"
+        "M  V30 END ATOM                                   \n"
+        "M  V30 BEGIN BOND                                 \n"
+        "M  V30 1 1 1 2                                    \n"
+        "M  V30 2 1 1 11 CFG=3                             \n"
+        "M  V30 3 1 1 12                                   \n"
+        "M  V30 4 1 2 3                                    \n"
+        "M  V30 5 1 2 10 CFG=1                             \n"
+        "M  V30 6 1 3 4                                    \n"
+        "M  V30 7 1 3 9 CFG=1                              \n"
+        "M  V30 8 1 4 5                                    \n"
+        "M  V30 9 1 4 8 CFG=1                              \n"
+        "M  V30 10 1 5 6                                   \n"
+        "M  V30 11 1 5 7 CFG=1                             \n"
+        "M  V30 12 1 12 13                                 \n"
+        "M  V30 13 1 12 18 CFG=3                           \n"
+        "M  V30 14 1 13 14                                 \n"
+        "M  V30 15 1 13 17 CFG=1                           \n"
+        "M  V30 16 1 14 15                                 \n"
+        "M  V30 17 1 14 16 CFG=1                           \n"
+        "M  V30 END BOND                                   \n"
+        "M  V30 BEGIN COLLECTION                           \n"
+        "M  V30 MDLV30/STERAC2 ATOMS=(1 1)                 \n"
+        "M  V30 MDLV30/STERAC1 ATOMS=(2 2 3)               \n"
+        "M  V30 MDLV30/STEABS ATOMS=(2 4 5)                \n"
+        "M  V30 MDLV30/STEREL1 ATOMS=(2 12 13)             \n"
+        "M  V30 MDLV30/STEREL2 ATOMS=(1 14)                \n"
+        "M  V30 END COLLECTION                             \n"
+        "M  V30 END CTAB                                   \n"
+        "M  END                                            \n";
+
+    char options[] = "-EnhancedStereochemistry";
+    inchi_Output output;
+    inchi_Output *poutput = &output;
+    const char expected_inchi[] = "InChI=1B/C10H14BrCl7/c1-3(11)5(13)7(15)9(17)10(18)8(16)6(14)4(2)12/h3-10H,1-2H3/t3-,4-,5+,6-,7-,8-,9+,10-/m0/s1(3,5)2(4)(6,8)3(7,9)(10)";
+
+    EXPECT_EQ(MakeINCHIFromMolfileText(molblock, options, poutput), 0);
+    EXPECT_STREQ(poutput->szInChI, expected_inchi);
+
+    poutput->szLog = nullptr;
+    poutput->szMessage = nullptr;
+
+    FreeINCHI(poutput);
+}
+
+TEST(test_enhancedStereo, test_EnhancedStereochemistry_2_atropisomer)
+{
+    const char *molblock =
+        "test_mol_atropisomer_1                        \n"
+        "  -INDIGO-02052611532D                       \n"
+        "                                             \n"
+        "  0  0  0  0  0  0  0  0  0  0  0 V3000      \n"
+        "M  V30 BEGIN CTAB                            \n"
+        "M  V30 COUNTS 16 17 0 0 0                    \n"
+        "M  V30 BEGIN ATOM                            \n"
+        "M  V30 1 C 6.11597 -6.27499 0.0 0            \n"
+        "M  V30 2 C 5.24996 -5.775 0.0 0              \n"
+        "M  V30 3 C 4.38395 -6.27499 0.0 0            \n"
+        "M  V30 4 C 4.38395 -7.27499 0.0 0            \n"
+        "M  V30 5 C 5.24996 -7.77498 0.0 0            \n"
+        "M  V30 6 C 6.11597 -7.27499 0.0 0            \n"
+        "M  V30 7 C 6.11605 -4.27501 0.0 0            \n"
+        "M  V30 8 C 5.24996 -4.775 0.0 0              \n"
+        "M  V30 9 C 4.38395 -4.27501 0.0 0            \n"
+        "M  V30 10 C 4.38395 -3.27501 0.0 0           \n"
+        "M  V30 11 C 6.11605 -3.27501 0.0 0           \n"
+        "M  V30 12 C 5.25004 -2.77502 0.0 0           \n"
+        "M  V30 13 Br 6.98205 -4.775 0.0 0            \n"
+        "M  V30 14 Cl 3.51795 -4.775 0.0 0            \n"
+        "M  V30 15 Cl 3.51795 -5.77492 0.0 0          \n"
+        "M  V30 16 Br 6.98205 -5.775 0.0 0            \n"
+        "M  V30 END ATOM                              \n"
+        "M  V30 BEGIN BOND                            \n"
+        "M  V30 1 1 1 6                               \n"
+        "M  V30 2 2 1 2                               \n"
+        "M  V30 3 1 2 3 CFG=1                         \n"
+        "M  V30 4 1 2 8                               \n"
+        "M  V30 5 2 3 4                               \n"
+        "M  V30 6 1 5 4                               \n"
+        "M  V30 7 2 5 6                               \n"
+        "M  V30 8 1 8 7 CFG=1                         \n"
+        "M  V30 9 2 7 11                              \n"
+        "M  V30 10 2 8 9                              \n"
+        "M  V30 11 1 9 10                             \n"
+        "M  V30 12 2 10 12                            \n"
+        "M  V30 13 1 12 11                            \n"
+        "M  V30 14 1 7 13                             \n"
+        "M  V30 15 1 9 14                             \n"
+        "M  V30 16 1 3 15                             \n"
+        "M  V30 17 1 1 16                             \n"
+        "M  V30 END BOND                              \n"
+        "M  V30 BEGIN COLLECTION                      \n"
+        "M  V30 MDLV30/STEABS ATOMS=(2 2 8)           \n"
+        "M  V30 END COLLECTION                        \n"
+        "M  V30 END CTAB                              \n"
+        "M  END                                       \n";
+
+    char options[] = "-EnhancedStereochemistry";
+    inchi_Output output;
+    inchi_Output *poutput = &output;
+    const char expected_inchi[] = "InChI=1B/C12H6Br2Cl2/c13-7-3-1-5-9(15)11(7)12-8(14)4-2-6-10(12)16/h1-6H";
+
+    EXPECT_EQ(MakeINCHIFromMolfileText(molblock, options, poutput), 0);
+    EXPECT_STREQ(poutput->szInChI, expected_inchi);
+
+    poutput->szLog = nullptr;
+    poutput->szMessage = nullptr;
+
+    FreeINCHI(poutput);
+}
+
+TEST(test_enhancedStereo, test_EnhancedStereochemistry_3_empty_collection_info)
+{
+    const char *molblock =
+        "broken_mol?                                \n"
+        "  -INDIGO-02062608442D                     \n"
+        "                                           \n"
+        "  0  0  0  0  0  0  0  0  0  0  0 V3000    \n"
+        "M  V30 BEGIN CTAB                          \n"
+        "M  V30 COUNTS 9 8 0 0 0                    \n"
+        "M  V30 BEGIN ATOM                          \n"
+        "M  V30 1 C 4.64199 -4.9 0.0 0              \n"
+        "M  V30 2 C 5.50801 -4.4 0.0 0 CFG=2        \n"
+        "M  V30 3 C 6.37404 -4.9 0.0 0 CFG=2        \n"
+        "M  V30 4 C 7.24006 -4.4 0.0 0 CFG=2        \n"
+        "M  V30 5 C 8.10609 -4.9 0.0 0              \n"
+        "M  V30 6 C 6.37404 -5.9 0.0 0              \n"
+        "M  V30 7 C 5.50801 -3.4 0.0 0              \n"
+        "M  V30 8 C 8.97211 -4.4 0.0 0              \n"
+        "M  V30 9 C 7.24006 -3.4 0.0 0              \n"
+        "M  V30 END ATOM                            \n"
+        "M  V30 BEGIN BOND                          \n"
+        "M  V30 1 1 1 2                             \n"
+        "M  V30 2 1 2 3                             \n"
+        "M  V30 3 1 3 4                             \n"
+        "M  V30 4 1 4 5                             \n"
+        "M  V30 5 1 3 6 CFG=3                       \n"
+        "M  V30 6 1 2 7 CFG=1                       \n"
+        "M  V30 7 1 5 8                             \n"
+        "M  V30 8 1 4 9 CFG=1                       \n"
+        "M  V30 END BOND                            \n"
+        "M  V30 BEGIN COLLECTION                    \n"
+        "M  V30 MDLV30/STERAC1 ATOMS=(1 )           \n"
+        "M  V30 MDLV30/STEABS ATOMS=(2  )           \n"
+        "M  V30 END COLLECTION                      \n"
+        "M  V30 END CTAB                            \n"
+        "M  END                                     \n";
+
+    char options[] = "-EnhancedStereochemistry";
+    inchi_Output output;
+    inchi_Output *poutput = &output;
+    const char expected_inchi[] = "InChI=1B/C9H20/c1-6-8(4)9(5)7(2)3/h7-9H,6H2,1-5H3/t8-,9+/m0";
+
+    EXPECT_EQ(MakeINCHIFromMolfileText(molblock, options, poutput), 0);
+    EXPECT_STREQ(poutput->szInChI, expected_inchi);
+
+    poutput->szLog = nullptr;
+    poutput->szMessage = nullptr;
+
+    FreeINCHI(poutput);
+}
+
+TEST(test_enhancedStereo, test_EnhancedStereochemistry_3_wrong_atoms_in_collection)
+{
+    const char *molblock =
+        "broken_mol?                                \n"
+        "  -INDIGO-02062608442D                     \n"
+        "                                           \n"
+        "  0  0  0  0  0  0  0  0  0  0  0 V3000    \n"
+        "M  V30 BEGIN CTAB                          \n"
+        "M  V30 COUNTS 9 8 0 0 0                    \n"
+        "M  V30 BEGIN ATOM                          \n"
+        "M  V30 1 C 4.64199 -4.9 0.0 0              \n"
+        "M  V30 2 C 5.50801 -4.4 0.0 0 CFG=2        \n"
+        "M  V30 3 C 6.37404 -4.9 0.0 0 CFG=2        \n"
+        "M  V30 4 C 7.24006 -4.4 0.0 0 CFG=2        \n"
+        "M  V30 5 C 8.10609 -4.9 0.0 0              \n"
+        "M  V30 6 C 6.37404 -5.9 0.0 0              \n"
+        "M  V30 7 C 5.50801 -3.4 0.0 0              \n"
+        "M  V30 8 C 8.97211 -4.4 0.0 0              \n"
+        "M  V30 9 C 7.24006 -3.4 0.0 0              \n"
+        "M  V30 END ATOM                            \n"
+        "M  V30 BEGIN BOND                          \n"
+        "M  V30 1 1 1 2                             \n"
+        "M  V30 2 1 2 3                             \n"
+        "M  V30 3 1 3 4                             \n"
+        "M  V30 4 1 4 5                             \n"
+        "M  V30 5 1 3 6 CFG=3                       \n"
+        "M  V30 6 1 2 7 CFG=1                       \n"
+        "M  V30 7 1 5 8                             \n"
+        "M  V30 8 1 4 9 CFG=1                       \n"
+        "M  V30 END BOND                            \n"
+        "M  V30 BEGIN COLLECTION                    \n"
+        "M  V30 MDLV30/STERAC1 ATOMS=(1 -2)         \n"
+        "M  V30 MDLV30/STEABS ATOMS=(2 13 43)       \n"
+        "M  V30 END COLLECTION                      \n"
+        "M  V30 END CTAB                            \n"
+        "M  END                                     \n";
+
+    char options[] = "-EnhancedStereochemistry";
+    inchi_Output output;
+    inchi_Output *poutput = &output;
+    const char expected_inchi[] = "InChI=1B/C9H20/c1-6-8(4)9(5)7(2)3/h7-9H,6H2,1-5H3/t8-,9+/m0";
+
+    EXPECT_EQ(MakeINCHIFromMolfileText(molblock, options, poutput), 0);
+    EXPECT_STREQ(poutput->szInChI, expected_inchi);
+
+    poutput->szLog = nullptr;
+    poutput->szMessage = nullptr;
+
+    FreeINCHI(poutput);
+}
+
+TEST(test_enhancedStereo, test_EnhancedStereochemistry_2_mols)
+{
+    const char *molblock =
+        "test_mol                                           \n"
+        "  -INDIGO-01232613552D                             \n"
+        "                                                   \n"
+        "  0  0  0  0  0  0  0  0  0  0  0 V3000            \n"
+        "M  V30 BEGIN CTAB                                  \n"
+        "M  V30 COUNTS 36 34 0 0 0                          \n"
+        "M  V30 BEGIN ATOM                                  \n"
+        "M  V30 1 C 5.83301 -3.275 0.0 0 CFG=1              \n"
+        "M  V30 2 C 4.96699 -2.775 0.0 0 CFG=1              \n"
+        "M  V30 3 C 4.10096 -3.275 0.0 0 CFG=2              \n"
+        "M  V30 4 C 3.23493 -2.775 0.0 0 CFG=1              \n"
+        "M  V30 5 C 2.36891 -3.275 0.0 0 CFG=2              \n"
+        "M  V30 6 C 1.50289 -2.775 0.0 0                    \n"
+        "M  V30 7 Br 2.36891 -4.275 0.0 0                   \n"
+        "M  V30 8 Cl 3.23493 -1.775 0.0 0                   \n"
+        "M  V30 9 Cl 4.10096 -4.275 0.0 0                   \n"
+        "M  V30 10 Cl 4.96699 -1.775 0.0 0                  \n"
+        "M  V30 11 Cl 5.83301 -4.275 0.0 0                  \n"
+        "M  V30 12 C 6.69904 -2.775 0.0 0 CFG=1             \n"
+        "M  V30 13 C 7.56506 -3.275 0.0 0 CFG=1             \n"
+        "M  V30 14 C 8.43109 -2.77501 0.0 0 CFG=2           \n"
+        "M  V30 15 C 9.29711 -3.275 0.0 0                   \n"
+        "M  V30 16 Cl 8.43109 -1.77501 0.0 0                \n"
+        "M  V30 17 Cl 7.56506 -4.275 0.0 0                  \n"
+        "M  V30 18 Cl 6.69904 -1.775 0.0 0                  \n"
+        "M  V30 19 C 6.13302 -7.62502 0.0 0 CFG=2           \n"
+        "M  V30 20 C 5.26698 -7.12498 0.0 0 CFG=1           \n"
+        "M  V30 21 C 4.40101 -7.62502 0.0 0 CFG=2           \n"
+        "M  V30 22 C 3.53496 -7.12498 0.0 0 CFG=1           \n"
+        "M  V30 23 C 2.66891 -7.62502 0.0 0 CFG=2           \n"
+        "M  V30 24 C 6.99899 -7.12498 0.0 0 CFG=2           \n"
+        "M  V30 25 C 7.86504 -7.62502 0.0 0 CFG=2           \n"
+        "M  V30 26 C 8.73109 -7.12498 0.0 0 CFG=2           \n"
+        "M  V30 27 C 1.80295 -7.12498 0.0 0                 \n"
+        "M  V30 28 Br 2.66891 -8.62501 0.0 0                \n"
+        "M  V30 29 Cl 3.53496 -6.12499 0.0 0                \n"
+        "M  V30 30 Cl 4.40101 -8.62501 0.0 0                \n"
+        "M  V30 31 Cl 5.26698 -6.12499 0.0 0                \n"
+        "M  V30 32 Cl 6.13302 -8.62501 0.0 0                \n"
+        "M  V30 33 C 9.59705 -7.62502 0.0 0                 \n"
+        "M  V30 34 Cl 8.73109 -6.12499 0.0 0                \n"
+        "M  V30 35 Cl 7.86504 -8.62501 0.0 0                \n"
+        "M  V30 36 Cl 6.99899 -6.12499 0.0 0                \n"
+        "M  V30 END ATOM                                    \n"
+        "M  V30 BEGIN BOND                                  \n"
+        "M  V30 1 1 1 2                                     \n"
+        "M  V30 2 1 1 11 CFG=3                              \n"
+        "M  V30 3 1 1 12                                    \n"
+        "M  V30 4 1 2 3                                     \n"
+        "M  V30 5 1 2 10 CFG=1                              \n"
+        "M  V30 6 1 3 4                                     \n"
+        "M  V30 7 1 3 9 CFG=1                               \n"
+        "M  V30 8 1 4 5                                     \n"
+        "M  V30 9 1 4 8 CFG=1                               \n"
+        "M  V30 10 1 5 6                                    \n"
+        "M  V30 11 1 5 7 CFG=1                              \n"
+        "M  V30 12 1 12 13                                  \n"
+        "M  V30 13 1 12 18 CFG=3                            \n"
+        "M  V30 14 1 13 14                                  \n"
+        "M  V30 15 1 13 17 CFG=1                            \n"
+        "M  V30 16 1 14 15                                  \n"
+        "M  V30 17 1 14 16 CFG=1                            \n"
+        "M  V30 18 1 19 20                                  \n"
+        "M  V30 19 1 20 21                                  \n"
+        "M  V30 20 1 21 22                                  \n"
+        "M  V30 21 1 22 23                                  \n"
+        "M  V30 22 1 19 24                                  \n"
+        "M  V30 23 1 24 25                                  \n"
+        "M  V30 24 1 25 26                                  \n"
+        "M  V30 25 1 23 27                                  \n"
+        "M  V30 26 1 23 28 CFG=1                            \n"
+        "M  V30 27 1 22 29 CFG=1                            \n"
+        "M  V30 28 1 21 30 CFG=1                            \n"
+        "M  V30 29 1 20 31 CFG=1                            \n"
+        "M  V30 30 1 19 32 CFG=3                            \n"
+        "M  V30 31 1 26 33                                  \n"
+        "M  V30 32 1 26 34 CFG=1                            \n"
+        "M  V30 33 1 25 35 CFG=3                            \n"
+        "M  V30 34 1 24 36 CFG=1                            \n"
+        "M  V30 END BOND                                    \n"
+        "M  V30 BEGIN COLLECTION                            \n"
+        "M  V30 MDLV30/STERAC2 ATOMS=(1 1)                  \n"
+        "M  V30 MDLV30/STERAC1 ATOMS=(2 2 3)                \n"
+        "M  V30 MDLV30/STEABS ATOMS=(4 4 5 22 23)           \n"
+        "M  V30 MDLV30/STEREL1 ATOMS=(2 12 13)              \n"
+        "M  V30 MDLV30/STEREL2 ATOMS=(1 14)                 \n"
+        "M  V30 MDLV30/STERAC4 ATOMS=(1 19)                 \n"
+        "M  V30 MDLV30/STERAC3 ATOMS=(2 20 21)              \n"
+        "M  V30 MDLV30/STEREL3 ATOMS=(2 24 25)              \n"
+        "M  V30 MDLV30/STEREL4 ATOMS=(1 26)                 \n"
+        "M  V30 END COLLECTION                              \n"
+        "M  V30 END CTAB                                    \n"
+        "M  END                                             \n";
+
+    char options[] = "-EnhancedStereochemistry";
+    inchi_Output output;
+    inchi_Output *poutput = &output;
+    const char expected_inchi[] = "InChI=1B/2C10H14BrCl7/c2*1-3(11)5(13)7(15)9(17)10(18)8(16)6(14)4(2)12/h2*3-10H,1-2H3/t2*3-,4-,5+,6-,7-,8-,9+,10-/m00/s2*1(3,5)2(4)(6,8)3(7,9)(10)";
+
+    EXPECT_EQ(MakeINCHIFromMolfileText(molblock, options, poutput), 0);
+    EXPECT_STREQ(poutput->szInChI, expected_inchi);
+
+    poutput->szLog = nullptr;
+    poutput->szMessage = nullptr;
+
+    FreeINCHI(poutput);
+}
+
+TEST(test_enhancedStereo, test_EnhancedStereochemistry_3_mols)
+{
+    const char *molblock =
+        "test mol                                            \n"
+        "  -INDIGO-01272609172D                              \n"
+        "													 \n"
+        "  0  0  0  0  0  0  0  0  0  0  0 V3000             \n"
+        "M  V30 BEGIN CTAB                                   \n"
+        "M  V30 COUNTS 44 41 0 0 0                           \n"
+        "M  V30 BEGIN ATOM                                   \n"
+        "M  V30 1 C 5.48304 -3.77499 0.0 0 CFG=1             \n"
+        "M  V30 2 C 4.61702 -3.27499 0.0 0 CFG=1             \n"
+        "M  V30 3 C 3.75099 -3.77499 0.0 0 CFG=2             \n"
+        "M  V30 4 C 2.88496 -3.27499 0.0 0 CFG=1             \n"
+        "M  V30 5 C 2.01894 -3.77499 0.0 0 CFG=2             \n"
+        "M  V30 6 C 1.15292 -3.27499 0.0 0                   \n"
+        "M  V30 7 Br 2.01894 -4.77499 0.0 0                  \n"
+        "M  V30 8 Cl 2.88496 -2.27499 0.0 0                  \n"
+        "M  V30 9 Cl 3.75099 -4.77499 0.0 0                  \n"
+        "M  V30 10 Cl 4.61702 -2.27499 0.0 0                 \n"
+        "M  V30 11 Cl 5.48304 -4.77499 0.0 0                 \n"
+        "M  V30 12 C 6.34907 -3.27499 0.0 0 CFG=1            \n"
+        "M  V30 13 C 7.21509 -3.77499 0.0 0 CFG=1            \n"
+        "M  V30 14 C 8.08112 -3.275 0.0 0 CFG=2              \n"
+        "M  V30 15 C 8.94714 -3.77499 0.0 0                  \n"
+        "M  V30 16 Cl 8.08112 -2.275 0.0 0                   \n"
+        "M  V30 17 Cl 7.21509 -4.77499 0.0 0                 \n"
+        "M  V30 18 Cl 6.34907 -2.27499 0.0 0                 \n"
+        "M  V30 19 C 5.78305 -8.12502 0.0 0 CFG=2            \n"
+        "M  V30 20 C 4.91701 -7.62498 0.0 0 CFG=1            \n"
+        "M  V30 21 C 4.05104 -8.12502 0.0 0 CFG=2            \n"
+        "M  V30 22 C 3.18499 -7.62498 0.0 0 CFG=1            \n"
+        "M  V30 23 C 2.31894 -8.12502 0.0 0 CFG=2            \n"
+        "M  V30 24 C 6.64902 -7.62498 0.0 0 CFG=2            \n"
+        "M  V30 25 C 7.51507 -8.12502 0.0 0 CFG=2            \n"
+        "M  V30 26 C 8.38112 -7.62498 0.0 0 CFG=2            \n"
+        "M  V30 27 C 1.45298 -7.62498 0.0 0                  \n"
+        "M  V30 28 Br 2.31894 -9.12501 0.0 0                 \n"
+        "M  V30 29 Cl 3.18499 -6.62499 0.0 0                 \n"
+        "M  V30 30 Cl 4.05104 -9.12501 0.0 0                 \n"
+        "M  V30 31 Cl 4.91701 -6.62499 0.0 0                 \n"
+        "M  V30 32 Cl 5.78305 -9.12501 0.0 0                 \n"
+        "M  V30 33 C 9.24708 -8.12502 0.0 0                  \n"
+        "M  V30 34 Cl 8.38112 -6.62499 0.0 0                 \n"
+        "M  V30 35 Cl 7.51507 -9.12501 0.0 0                 \n"
+        "M  V30 36 Cl 6.64902 -6.62499 0.0 0                 \n"
+        "M  V30 37 C 14.367 -4.45 0.0 0 CFG=1                \n"
+        "M  V30 38 C 15.233 -3.95 0.0 0 CFG=2                \n"
+        "M  V30 39 C 16.099 -4.45 0.0 0                      \n"
+        "M  V30 40 C 15.233 -2.95 0.0 0                      \n"
+        "M  V30 41 C 13.501 -3.95 0.0 0 CFG=1                \n"
+        "M  V30 42 C 12.6349 -4.45 0.0 0                     \n"
+        "M  V30 43 C 13.501 -2.95 0.0 0                      \n"
+        "M  V30 44 C 14.367 -5.45 0.0 0                      \n"
+        "M  V30 END ATOM                                     \n"
+        "M  V30 BEGIN BOND                                   \n"
+        "M  V30 1 1 1 2                                      \n"
+        "M  V30 2 1 1 11 CFG=3                               \n"
+        "M  V30 3 1 1 12                                     \n"
+        "M  V30 4 1 2 3                                      \n"
+        "M  V30 5 1 2 10 CFG=1                               \n"
+        "M  V30 6 1 3 4                                      \n"
+        "M  V30 7 1 3 9 CFG=1                                \n"
+        "M  V30 8 1 4 5                                      \n"
+        "M  V30 9 1 4 8 CFG=1                                \n"
+        "M  V30 10 1 5 6                                     \n"
+        "M  V30 11 1 5 7 CFG=1                               \n"
+        "M  V30 12 1 12 13                                   \n"
+        "M  V30 13 1 12 18 CFG=3                             \n"
+        "M  V30 14 1 13 14                                   \n"
+        "M  V30 15 1 13 17 CFG=1                             \n"
+        "M  V30 16 1 14 15                                   \n"
+        "M  V30 17 1 14 16 CFG=1                             \n"
+        "M  V30 18 1 19 20                                   \n"
+        "M  V30 19 1 20 21                                   \n"
+        "M  V30 20 1 21 22                                   \n"
+        "M  V30 21 1 22 23                                   \n"
+        "M  V30 22 1 19 24                                   \n"
+        "M  V30 23 1 24 25                                   \n"
+        "M  V30 24 1 25 26                                   \n"
+        "M  V30 25 1 23 27                                   \n"
+        "M  V30 26 1 23 28 CFG=1                             \n"
+        "M  V30 27 1 22 29 CFG=1                             \n"
+        "M  V30 28 1 21 30 CFG=1                             \n"
+        "M  V30 29 1 20 31 CFG=1                             \n"
+        "M  V30 30 1 19 32 CFG=3                             \n"
+        "M  V30 31 1 26 33                                   \n"
+        "M  V30 32 1 26 34 CFG=1                             \n"
+        "M  V30 33 1 25 35 CFG=3                             \n"
+        "M  V30 34 1 24 36 CFG=1                             \n"
+        "M  V30 35 1 37 38                                   \n"
+        "M  V30 36 1 38 39                                   \n"
+        "M  V30 37 1 38 40 CFG=1                             \n"
+        "M  V30 38 1 37 41                                   \n"
+        "M  V30 39 1 41 42                                   \n"
+        "M  V30 40 1 41 43 CFG=1                             \n"
+        "M  V30 41 1 37 44 CFG=3                             \n"
+        "M  V30 END BOND                                     \n"
+        "M  V30 BEGIN COLLECTION                             \n"
+        "M  V30 MDLV30/STERAC2 ATOMS=(1 1)                   \n"
+        "M  V30 MDLV30/STERAC1 ATOMS=(2 2 3)                 \n"
+        "M  V30 MDLV30/STEABS ATOMS=(5 4 5 22 23 38)         \n"
+        "M  V30 MDLV30/STEREL1 ATOMS=(2 12 13)               \n"
+        "M  V30 MDLV30/STEREL2 ATOMS=(1 14)                  \n"
+        "M  V30 MDLV30/STERAC4 ATOMS=(1 19)                  \n"
+        "M  V30 MDLV30/STERAC3 ATOMS=(2 20 21)               \n"
+        "M  V30 MDLV30/STEREL3 ATOMS=(2 24 25)               \n"
+        "M  V30 MDLV30/STEREL4 ATOMS=(1 26)                  \n"
+        "M  V30 MDLV30/STERAC5 ATOMS=(2 37 41)               \n"
+        "M  V30 END COLLECTION                               \n"
+        "M  V30 END CTAB                                     \n"
+        "M  END                                              \n";
+
+
+    char options[] = "-EnhancedStereochemistry";
+    inchi_Output output;
+    inchi_Output *poutput = &output;
+    const char expected_inchi[] = "InChI=1B/2C10H14BrCl7.C8H18/c2*1-3(11)5(13)7(15)9(17)10(18)8(16)6(14)4(2)12;1-6(2)8(5)7(3)4/h2*3-10H,1-2H3;6-8H,1-5H3/t2*3-,4-,5+,6-,7-,8-,9+,10-;/m00./s2*1(3,5)2(4)(6,8)3(7,9)(10);1(6)3(7,8)";
+
+    EXPECT_EQ(MakeINCHIFromMolfileText(molblock, options, poutput), 0);
+    EXPECT_STREQ(poutput->szInChI, expected_inchi);
+
+    poutput->szLog = nullptr;
+    poutput->szMessage = nullptr;
+
+    FreeINCHI(poutput);
+}
+
+TEST(test_enhancedStereo, test_EnhancedStereochemistry_4_mols)
+{
+    const char *molblock =
+        "test_mol                                                              \n"
+        "  -INDIGO-01272609502D                                                \n"
+        "                                                                      \n"
+        "  0  0  0  0  0  0  0  0  0  0  0 V3000                               \n"
+        "M  V30 BEGIN CTAB                                                     \n"
+        "M  V30 COUNTS 57 53 0 0 0                                             \n"
+        "M  V30 BEGIN ATOM                                                     \n"
+        "M  V30 1 C 5.48304 -3.77499 0.0 0 CFG=1                               \n"
+        "M  V30 2 C 4.61702 -3.27499 0.0 0 CFG=1                               \n"
+        "M  V30 3 C 3.75099 -3.77499 0.0 0 CFG=2                               \n"
+        "M  V30 4 C 2.88496 -3.27499 0.0 0 CFG=1                               \n"
+        "M  V30 5 C 2.01894 -3.77499 0.0 0 CFG=2                               \n"
+        "M  V30 6 C 1.15292 -3.27499 0.0 0                                     \n"
+        "M  V30 7 Br 2.01894 -4.77499 0.0 0                                    \n"
+        "M  V30 8 Cl 2.88496 -2.27499 0.0 0                                    \n"
+        "M  V30 9 Cl 3.75099 -4.77499 0.0 0                                    \n"
+        "M  V30 10 Cl 4.61702 -2.27499 0.0 0                                   \n"
+        "M  V30 11 Cl 5.48304 -4.77499 0.0 0                                   \n"
+        "M  V30 12 C 6.34907 -3.27499 0.0 0 CFG=1                              \n"
+        "M  V30 13 C 7.21509 -3.77499 0.0 0 CFG=1                              \n"
+        "M  V30 14 C 8.08112 -3.275 0.0 0 CFG=2                                \n"
+        "M  V30 15 C 8.94714 -3.77499 0.0 0                                    \n"
+        "M  V30 16 Cl 8.08112 -2.275 0.0 0                                     \n"
+        "M  V30 17 Cl 7.21509 -4.77499 0.0 0                                   \n"
+        "M  V30 18 Cl 6.34907 -2.27499 0.0 0                                   \n"
+        "M  V30 19 C 5.78305 -8.12502 0.0 0 CFG=2                              \n"
+        "M  V30 20 C 4.91701 -7.62498 0.0 0 CFG=1                              \n"
+        "M  V30 21 C 4.05104 -8.12502 0.0 0 CFG=2                              \n"
+        "M  V30 22 C 3.18499 -7.62498 0.0 0 CFG=1                              \n"
+        "M  V30 23 C 2.31894 -8.12502 0.0 0 CFG=2                              \n"
+        "M  V30 24 C 6.64902 -7.62498 0.0 0 CFG=2                              \n"
+        "M  V30 25 C 7.51507 -8.12502 0.0 0 CFG=2                              \n"
+        "M  V30 26 C 8.38112 -7.62498 0.0 0 CFG=2                              \n"
+        "M  V30 27 C 1.45298 -7.62498 0.0 0                                    \n"
+        "M  V30 28 Br 2.31894 -9.12501 0.0 0                                   \n"
+        "M  V30 29 Cl 3.18499 -6.62499 0.0 0                                   \n"
+        "M  V30 30 Cl 4.05104 -9.12501 0.0 0                                   \n"
+        "M  V30 31 Cl 4.91701 -6.62499 0.0 0                                   \n"
+        "M  V30 32 Cl 5.78305 -9.12501 0.0 0                                   \n"
+        "M  V30 33 C 9.24708 -8.12502 0.0 0                                    \n"
+        "M  V30 34 Cl 8.38112 -6.62499 0.0 0                                   \n"
+        "M  V30 35 Cl 7.51507 -9.12501 0.0 0                                   \n"
+        "M  V30 36 Cl 6.64902 -6.62499 0.0 0                                   \n"
+        "M  V30 37 C 14.367 -4.45 0.0 0 CFG=1                                  \n"
+        "M  V30 38 C 15.233 -3.95 0.0 0 CFG=2                                  \n"
+        "M  V30 39 C 16.099 -4.45 0.0 0                                        \n"
+        "M  V30 40 C 15.233 -2.95 0.0 0                                        \n"
+        "M  V30 41 C 13.501 -3.95 0.0 0 CFG=1                                  \n"
+        "M  V30 42 C 12.6349 -4.45 0.0 0                                       \n"
+        "M  V30 43 C 13.501 -2.95 0.0 0                                        \n"
+        "M  V30 44 C 14.367 -5.45 0.0 0                                        \n"
+        "M  V30 45 C 11.7689 -3.95 0.0 0                                       \n"
+        "M  V30 46 C 11.417 -7.75 0.0 0                                        \n"
+        "M  V30 47 C 12.283 -7.25 0.0 0 CFG=2                                  \n"
+        "M  V30 48 C 13.149 -7.75 0.0 0                                        \n"
+        "M  V30 49 C 14.0151 -7.25 0.0 0 CFG=2                                 \n"
+        "M  V30 50 C 14.8811 -7.75 0.0 0                                       \n"
+        "M  V30 51 C 13.149 -8.75 0.0 0 CFG=2                                  \n"
+        "M  V30 52 C 12.283 -9.25 0.0 0                                        \n"
+        "M  V30 53 C 14.0151 -9.25 0.0 0 CFG=2                                 \n"
+        "M  V30 54 C 14.0151 -10.25 0.0 0                                      \n"
+        "M  V30 55 C 14.8811 -8.75 0.0 0                                       \n"
+        "M  V30 56 C 14.0151 -6.25 0.0 0                                       \n"
+        "M  V30 57 C 12.283 -6.25 0.0 0                                        \n"
+        "M  V30 END ATOM                                                       \n"
+        "M  V30 BEGIN BOND                                                     \n"
+        "M  V30 1 1 1 2                                                        \n"
+        "M  V30 2 1 1 11 CFG=3                                                 \n"
+        "M  V30 3 1 1 12                                                       \n"
+        "M  V30 4 1 2 3                                                        \n"
+        "M  V30 5 1 2 10 CFG=1                                                 \n"
+        "M  V30 6 1 3 4                                                        \n"
+        "M  V30 7 1 3 9 CFG=1                                                  \n"
+        "M  V30 8 1 4 5                                                        \n"
+        "M  V30 9 1 4 8 CFG=1                                                  \n"
+        "M  V30 10 1 5 6                                                       \n"
+        "M  V30 11 1 5 7 CFG=1                                                 \n"
+        "M  V30 12 1 12 13                                                     \n"
+        "M  V30 13 1 12 18 CFG=3                                               \n"
+        "M  V30 14 1 13 14                                                     \n"
+        "M  V30 15 1 13 17 CFG=1                                               \n"
+        "M  V30 16 1 14 15                                                     \n"
+        "M  V30 17 1 14 16 CFG=1                                               \n"
+        "M  V30 18 1 19 20                                                     \n"
+        "M  V30 19 1 20 21                                                     \n"
+        "M  V30 20 1 21 22                                                     \n"
+        "M  V30 21 1 22 23                                                     \n"
+        "M  V30 22 1 19 24                                                     \n"
+        "M  V30 23 1 24 25                                                     \n"
+        "M  V30 24 1 25 26                                                     \n"
+        "M  V30 25 1 23 27                                                     \n"
+        "M  V30 26 1 23 28 CFG=1                                               \n"
+        "M  V30 27 1 22 29 CFG=1                                               \n"
+        "M  V30 28 1 21 30 CFG=1                                               \n"
+        "M  V30 29 1 20 31 CFG=1                                               \n"
+        "M  V30 30 1 19 32 CFG=3                                               \n"
+        "M  V30 31 1 26 33                                                     \n"
+        "M  V30 32 1 26 34 CFG=1                                               \n"
+        "M  V30 33 1 25 35 CFG=3                                               \n"
+        "M  V30 34 1 24 36 CFG=1                                               \n"
+        "M  V30 35 1 37 38                                                     \n"
+        "M  V30 36 1 38 39                                                     \n"
+        "M  V30 37 1 38 40 CFG=1                                               \n"
+        "M  V30 38 1 37 41                                                     \n"
+        "M  V30 39 1 41 42                                                     \n"
+        "M  V30 40 1 41 43 CFG=1                                               \n"
+        "M  V30 41 1 37 44 CFG=3                                               \n"
+        "M  V30 42 1 42 45                                                     \n"
+        "M  V30 43 1 46 47                                                     \n"
+        "M  V30 44 1 47 48                                                     \n"
+        "M  V30 45 1 48 49                                                     \n"
+        "M  V30 46 1 49 50                                                     \n"
+        "M  V30 47 1 48 51                                                     \n"
+        "M  V30 48 1 51 52 CFG=1                                               \n"
+        "M  V30 49 1 51 53                                                     \n"
+        "M  V30 50 1 53 54                                                     \n"
+        "M  V30 51 1 53 55 CFG=1                                               \n"
+        "M  V30 52 1 49 56 CFG=1                                               \n"
+        "M  V30 53 1 47 57 CFG=1                                               \n"
+        "M  V30 END BOND                                                       \n"
+        "M  V30 BEGIN COLLECTION                                               \n"
+        "M  V30 MDLV30/STERAC2 ATOMS=(1 1)                                     \n"
+        "M  V30 MDLV30/STERAC1 ATOMS=(2 2 3)                                   \n"
+        "M  V30 MDLV30/STEABS ATOMS=(9 4 5 22 23 38 47 49 51 53)               \n"
+        "M  V30 MDLV30/STEREL1 ATOMS=(2 12 13)                                 \n"
+        "M  V30 MDLV30/STEREL2 ATOMS=(1 14)                                    \n"
+        "M  V30 MDLV30/STERAC4 ATOMS=(1 19)                                    \n"
+        "M  V30 MDLV30/STERAC3 ATOMS=(2 20 21)                                 \n"
+        "M  V30 MDLV30/STEREL3 ATOMS=(2 24 25)                                 \n"
+        "M  V30 MDLV30/STEREL4 ATOMS=(1 26)                                    \n"
+        "M  V30 MDLV30/STERAC5 ATOMS=(2 37 41)                                 \n"
+        "M  V30 END COLLECTION                                                 \n"
+        "M  V30 END CTAB                                                       \n"
+        "M  END                                                                \n";
+
+
+    char options[] = "-EnhancedStereochemistry";
+    inchi_Output output;
+    inchi_Output *poutput = &output;
+    const char expected_inchi[] = "InChI=1B/C12H26.2C10H14BrCl7.C9H20/c1-8(2)11(7)12(9(3)4)10(5)6;2*1-3(11)5(13)7(15)9(17)10(18)8(16)6(14)4(2)12;1-6-8(4)9(5)7(2)3/h8-12H,1-7H3;2*3-10H,1-2H3;7-9H,6H2,1-5H3/t11-;2*3-,4-,5+,6-,7-,8-,9+,10-;8-,9+/m1001/s1(8,9,10,11);2*1(3,5)2(4)(6,8)3(7,9)(10);1(7)3(8,9)";
+
+    EXPECT_EQ(MakeINCHIFromMolfileText(molblock, options, poutput), 0);
+    EXPECT_STREQ(poutput->szInChI, expected_inchi);
+
+    poutput->szLog = nullptr;
+    poutput->szMessage = nullptr;
+
+    FreeINCHI(poutput);
+}
+
+TEST(test_enhancedStereo, test_EnhancedStereochemistry_2_mols_inter_enhstereo_grps_1)
+{
+    const char *molblock =
+        "my_test_mol                                      \n"
+        "  -INDIGO-01232613442D                           \n"
+        "                                                 \n"
+        "  0  0  0  0  0  0  0  0  0  0  0 V3000          \n"
+        "M  V30 BEGIN CTAB                                \n"
+        "M  V30 COUNTS 36 34 0 0 0                        \n"
+        "M  V30 BEGIN ATOM                                \n"
+        "M  V30 1 C 5.83301 -3.275 0.0 0 CFG=1            \n"
+        "M  V30 2 C 4.96699 -2.775 0.0 0 CFG=1            \n"
+        "M  V30 3 C 4.10096 -3.275 0.0 0 CFG=2            \n"
+        "M  V30 4 C 3.23493 -2.775 0.0 0 CFG=1            \n"
+        "M  V30 5 C 2.36891 -3.275 0.0 0 CFG=2            \n"
+        "M  V30 6 C 1.50289 -2.775 0.0 0                  \n"
+        "M  V30 7 Br 2.36891 -4.275 0.0 0                 \n"
+        "M  V30 8 Cl 3.23493 -1.775 0.0 0                 \n"
+        "M  V30 9 Cl 4.10096 -4.275 0.0 0                 \n"
+        "M  V30 10 Cl 4.96699 -1.775 0.0 0                \n"
+        "M  V30 11 Cl 5.83301 -4.275 0.0 0                \n"
+        "M  V30 12 C 6.69904 -2.775 0.0 0 CFG=1           \n"
+        "M  V30 13 C 7.56506 -3.275 0.0 0 CFG=1           \n"
+        "M  V30 14 C 8.43109 -2.77501 0.0 0 CFG=2         \n"
+        "M  V30 15 C 9.29711 -3.275 0.0 0                 \n"
+        "M  V30 16 Cl 8.43109 -1.77501 0.0 0              \n"
+        "M  V30 17 Cl 7.56506 -4.275 0.0 0                \n"
+        "M  V30 18 Cl 6.69904 -1.775 0.0 0                \n"
+        "M  V30 19 C 6.13302 -7.62502 0.0 0 CFG=2         \n"
+        "M  V30 20 C 5.26698 -7.12498 0.0 0 CFG=1         \n"
+        "M  V30 21 C 4.40101 -7.62502 0.0 0 CFG=2         \n"
+        "M  V30 22 C 3.53496 -7.12498 0.0 0 CFG=1         \n"
+        "M  V30 23 C 2.66891 -7.62502 0.0 0 CFG=2         \n"
+        "M  V30 24 C 6.99899 -7.12498 0.0 0 CFG=2         \n"
+        "M  V30 25 C 7.86504 -7.62502 0.0 0 CFG=2         \n"
+        "M  V30 26 C 8.73109 -7.12498 0.0 0 CFG=2         \n"
+        "M  V30 27 C 1.80295 -7.12498 0.0 0               \n"
+        "M  V30 28 Br 2.66891 -8.62501 0.0 0              \n"
+        "M  V30 29 Cl 3.53496 -6.12499 0.0 0              \n"
+        "M  V30 30 Cl 4.40101 -8.62501 0.0 0              \n"
+        "M  V30 31 Cl 5.26698 -6.12499 0.0 0              \n"
+        "M  V30 32 Cl 6.13302 -8.62501 0.0 0              \n"
+        "M  V30 33 C 9.59705 -7.62502 0.0 0               \n"
+        "M  V30 34 Cl 8.73109 -6.12499 0.0 0              \n"
+        "M  V30 35 Cl 7.86504 -8.62501 0.0 0              \n"
+        "M  V30 36 Cl 6.99899 -6.12499 0.0 0              \n"
+        "M  V30 END ATOM                                  \n"
+        "M  V30 BEGIN BOND                                \n"
+        "M  V30 1 1 1 2                                   \n"
+        "M  V30 2 1 1 11 CFG=3                            \n"
+        "M  V30 3 1 1 12                                  \n"
+        "M  V30 4 1 2 3                                   \n"
+        "M  V30 5 1 2 10 CFG=1                            \n"
+        "M  V30 6 1 3 4                                   \n"
+        "M  V30 7 1 3 9 CFG=1                             \n"
+        "M  V30 8 1 4 5                                   \n"
+        "M  V30 9 1 4 8 CFG=1                             \n"
+        "M  V30 10 1 5 6                                  \n"
+        "M  V30 11 1 5 7 CFG=1                            \n"
+        "M  V30 12 1 12 13                                \n"
+        "M  V30 13 1 12 18 CFG=3                          \n"
+        "M  V30 14 1 13 14                                \n"
+        "M  V30 15 1 13 17 CFG=1                          \n"
+        "M  V30 16 1 14 15                                \n"
+        "M  V30 17 1 14 16 CFG=1                          \n"
+        "M  V30 18 1 19 20                                \n"
+        "M  V30 19 1 20 21                                \n"
+        "M  V30 20 1 21 22                                \n"
+        "M  V30 21 1 22 23                                \n"
+        "M  V30 22 1 19 24                                \n"
+        "M  V30 23 1 24 25                                \n"
+        "M  V30 24 1 25 26                                \n"
+        "M  V30 25 1 23 27                                \n"
+        "M  V30 26 1 23 28 CFG=1                          \n"
+        "M  V30 27 1 22 29 CFG=1                          \n"
+        "M  V30 28 1 21 30 CFG=1                          \n"
+        "M  V30 29 1 20 31 CFG=1                          \n"
+        "M  V30 30 1 19 32 CFG=3                          \n"
+        "M  V30 31 1 26 33                                \n"
+        "M  V30 32 1 26 34 CFG=1                          \n"
+        "M  V30 33 1 25 35 CFG=3                          \n"
+        "M  V30 34 1 24 36 CFG=1                          \n"
+        "M  V30 END BOND                                  \n"
+        "M  V30 BEGIN COLLECTION                          \n"
+        "M  V30 MDLV30/STERAC2 ATOMS=(2 1 19)             \n"
+        "M  V30 MDLV30/STERAC1 ATOMS=(4 2 3 20 21)        \n"
+        "M  V30 MDLV30/STEABS ATOMS=(4 4 5 22 23)         \n"
+        "M  V30 MDLV30/STEREL1 ATOMS=(4 12 13 24 25)      \n"
+        "M  V30 MDLV30/STEREL2 ATOMS=(2 14 26)            \n"
+        "M  V30 END COLLECTION                            \n"
+        "M  V30 END CTAB                                  \n"
+        "M  END                                           \n";
+
+    char options[] = "-EnhancedStereochemistry";
+    inchi_Output output;
+    inchi_Output *poutput = &output;
+    const char expected_inchi[] = "InChI=1B/2C10H14BrCl7/c2*1-3(11)5(13)7(15)9(17)10(18)8(16)6(14)4(2)12/h2*3-10H,1-2H3/t2*3-,4-,5+,6-,7-,8-,9+,10-/m00/s2*1(3,5)2(4)(6,8)3(7,9)(10)";
+
+    EXPECT_EQ(MakeINCHIFromMolfileText(molblock, options, poutput), 0);
+    EXPECT_STREQ(poutput->szInChI, expected_inchi);
+
+    poutput->szLog = nullptr;
+    poutput->szMessage = nullptr;
+
+    FreeINCHI(poutput);
+}
+
+TEST(test_enhancedStereo, test_EnhancedStereochemistry_2_mols_inter_enhstereo_grps_2)
+{
+    const char *molblock =
+        "test_mol                                              \n"
+        "  -INDIGO-02042609012D                                \n"
+        "                                                      \n"
+        "  0  0  0  0  0  0  0  0  0  0  0 V3000               \n"
+        "M  V30 BEGIN CTAB                                     \n"
+        "M  V30 COUNTS 18 16 0 0 0                             \n"
+        "M  V30 BEGIN ATOM                                     \n"
+        "M  V30 1 C 3.06699 -3.575 0.0 0                       \n"
+        "M  V30 2 C 3.93301 -3.075 0.0 0                       \n"
+        "M  V30 3 C 4.79904 -3.575 0.0 0 CFG=1                 \n"
+        "M  V30 4 C 5.66506 -3.075 0.0 0 CFG=2                 \n"
+        "M  V30 5 C 6.53109 -3.575 0.0 0                       \n"
+        "M  V30 6 C 7.39711 -3.075 0.0 0                       \n"
+        "M  V30 7 C 4.79904 -4.575 0.0 0                       \n"
+        "M  V30 8 C 5.66506 -2.075 0.0 0                       \n"
+        "M  V30 9 C 3.06699 -8.475 0.0 0                       \n"
+        "M  V30 10 C 3.93301 -7.975 0.0 0 CFG=2                \n"
+        "M  V30 11 C 4.79904 -8.475 0.0 0 CFG=2                \n"
+        "M  V30 12 C 5.66506 -7.975 0.0 0                      \n"
+        "M  V30 13 C 6.53109 -8.475 0.0 0                      \n"
+        "M  V30 14 C 3.93301 -6.975 0.0 0                      \n"
+        "M  V30 15 C 4.79904 -9.475 0.0 0                      \n"
+        "M  V30 16 C 7.39711 -7.975 0.0 0                      \n"
+        "M  V30 17 C 8.26314 -8.475 0.0 0                      \n"
+        "M  V30 18 C 9.12916 -7.975 0.0 0                      \n"
+        "M  V30 END ATOM                                       \n"
+        "M  V30 BEGIN BOND                                     \n"
+        "M  V30 1 1 1 2                                        \n"
+        "M  V30 2 1 2 3                                        \n"
+        "M  V30 3 1 3 4                                        \n"
+        "M  V30 4 1 4 5                                        \n"
+        "M  V30 5 1 5 6                                        \n"
+        "M  V30 6 1 3 7 CFG=1                                  \n"
+        "M  V30 7 1 4 8 CFG=1                                  \n"
+        "M  V30 8 1 9 10                                       \n"
+        "M  V30 9 1 10 11                                      \n"
+        "M  V30 10 1 11 12                                     \n"
+        "M  V30 11 1 12 13                                     \n"
+        "M  V30 12 1 10 14 CFG=1                               \n"
+        "M  V30 13 1 11 15 CFG=3                               \n"
+        "M  V30 14 1 13 16                                     \n"
+        "M  V30 15 1 16 17                                     \n"
+        "M  V30 16 1 17 18                                     \n"
+        "M  V30 END BOND                                       \n"
+        "M  V30 BEGIN COLLECTION                               \n"
+        "M  V30 MDLV30/STEABS ATOMS=(2 3 11)                   \n"
+        "M  V30 MDLV30/STERAC1 ATOMS=(2 4 10)                  \n"
+        "M  V30 END COLLECTION                                 \n"
+        "M  V30 END CTAB                                       \n"
+        "M  END                                                \n";
+
+
+    char options[] = "-EnhancedStereochemistry";
+    inchi_Output output;
+    inchi_Output *poutput = &output;
+    const char expected_inchi[] = "InChI=1B/C10H22.C8H18/c1-5-6-7-8-10(4)9(2)3;1-5-7(3)8(4)6-2/h9-10H,5-8H2,1-4H3;7-8H,5-6H2,1-4H3/t10-;7-,8-/m00/s1(10)3(9);1(7)3(8)";
+
+    EXPECT_EQ(MakeINCHIFromMolfileText(molblock, options, poutput), 0);
+    EXPECT_STREQ(poutput->szInChI, expected_inchi);
+
+    poutput->szLog = nullptr;
+    poutput->szMessage = nullptr;
+
+    FreeINCHI(poutput);
+}
+
+TEST(test_enhancedStereo, test_EnhancedStereochemistry_2_different_mols_inter_enhstereo_grps)
+{
+    const char *molblock =
+        "test_mols                                                \n"
+        "  -INDIGO-01272610042D                                   \n"
+        "                                                         \n"
+        "  0  0  0  0  0  0  0  0  0  0  0 V3000                  \n"
+        "M  V30 BEGIN CTAB                                        \n"
+        "M  V30 COUNTS 37 35 0 0 0                                \n"
+        "M  V30 BEGIN ATOM                                        \n"
+        "M  V30 1 C 5.43304 -3.47499 0.0 0 CFG=1                  \n"
+        "M  V30 2 C 4.56702 -2.97499 0.0 0 CFG=1                  \n"
+        "M  V30 3 C 3.70099 -3.47499 0.0 0 CFG=2                  \n"
+        "M  V30 4 C 2.83496 -2.97499 0.0 0 CFG=1                  \n"
+        "M  V30 5 C 1.96894 -3.47499 0.0 0 CFG=2                  \n"
+        "M  V30 6 C 1.10292 -2.97499 0.0 0                        \n"
+        "M  V30 7 Br 1.96894 -4.47499 0.0 0                       \n"
+        "M  V30 8 Cl 2.83496 -1.97499 0.0 0                       \n"
+        "M  V30 9 Cl 3.70099 -4.47499 0.0 0                       \n"
+        "M  V30 10 Cl 4.56702 -1.97499 0.0 0                      \n"
+        "M  V30 11 Cl 5.43304 -4.47499 0.0 0                      \n"
+        "M  V30 12 C 6.29907 -2.97499 0.0 0 CFG=1                 \n"
+        "M  V30 13 C 7.16509 -3.47499 0.0 0 CFG=1                 \n"
+        "M  V30 14 C 8.03112 -2.975 0.0 0 CFG=2                   \n"
+        "M  V30 15 C 8.89714 -3.47499 0.0 0                       \n"
+        "M  V30 16 Cl 8.03112 -1.975 0.0 0                        \n"
+        "M  V30 17 Cl 7.16509 -4.47499 0.0 0                      \n"
+        "M  V30 18 Cl 6.29907 -1.97499 0.0 0                      \n"
+        "M  V30 19 C 5.73305 -7.82502 0.0 0 CFG=2                 \n"
+        "M  V30 20 C 4.86701 -7.32498 0.0 0 CFG=1                 \n"
+        "M  V30 21 C 4.00104 -7.82502 0.0 0 CFG=2                 \n"
+        "M  V30 22 C 3.13499 -7.32498 0.0 0 CFG=1                 \n"
+        "M  V30 23 C 2.26894 -7.82502 0.0 0 CFG=2                 \n"
+        "M  V30 24 C 6.59902 -7.32498 0.0 0 CFG=2                 \n"
+        "M  V30 25 C 7.46507 -7.82502 0.0 0 CFG=2                 \n"
+        "M  V30 26 C 8.33112 -7.32498 0.0 0 CFG=2                 \n"
+        "M  V30 27 C 1.40298 -7.32498 0.0 0                       \n"
+        "M  V30 28 Br 2.26894 -8.82501 0.0 0                      \n"
+        "M  V30 29 Cl 3.13499 -6.32499 0.0 0                      \n"
+        "M  V30 30 Cl 4.00104 -8.82501 0.0 0                      \n"
+        "M  V30 31 Cl 4.86701 -6.32499 0.0 0                      \n"
+        "M  V30 32 Cl 5.73305 -8.82501 0.0 0                      \n"
+        "M  V30 33 C 9.19708 -7.82502 0.0 0                       \n"
+        "M  V30 34 Cl 8.33112 -6.32499 0.0 0                      \n"
+        "M  V30 35 Cl 7.46507 -8.82501 0.0 0                      \n"
+        "M  V30 36 Cl 6.59902 -6.32499 0.0 0                      \n"
+        "M  V30 37 C 9.19702 -8.82502 0.0 0                       \n"
+        "M  V30 END ATOM                                          \n"
+        "M  V30 BEGIN BOND                                        \n"
+        "M  V30 1 1 1 2                                           \n"
+        "M  V30 2 1 1 11 CFG=3                                    \n"
+        "M  V30 3 1 1 12                                          \n"
+        "M  V30 4 1 2 3                                           \n"
+        "M  V30 5 1 2 10 CFG=1                                    \n"
+        "M  V30 6 1 3 4                                           \n"
+        "M  V30 7 1 3 9 CFG=1                                     \n"
+        "M  V30 8 1 4 5                                           \n"
+        "M  V30 9 1 4 8 CFG=1                                     \n"
+        "M  V30 10 1 5 6                                          \n"
+        "M  V30 11 1 5 7 CFG=1                                    \n"
+        "M  V30 12 1 12 13                                        \n"
+        "M  V30 13 1 12 18 CFG=3                                  \n"
+        "M  V30 14 1 13 14                                        \n"
+        "M  V30 15 1 13 17 CFG=1                                  \n"
+        "M  V30 16 1 14 15                                        \n"
+        "M  V30 17 1 14 16 CFG=1                                  \n"
+        "M  V30 18 1 19 20                                        \n"
+        "M  V30 19 1 20 21                                        \n"
+        "M  V30 20 1 21 22                                        \n"
+        "M  V30 21 1 22 23                                        \n"
+        "M  V30 22 1 19 24                                        \n"
+        "M  V30 23 1 24 25                                        \n"
+        "M  V30 24 1 25 26                                        \n"
+        "M  V30 25 1 23 27                                        \n"
+        "M  V30 26 1 23 28 CFG=1                                  \n"
+        "M  V30 27 1 22 29 CFG=1                                  \n"
+        "M  V30 28 1 21 30 CFG=1                                  \n"
+        "M  V30 29 1 20 31 CFG=1                                  \n"
+        "M  V30 30 1 19 32 CFG=3                                  \n"
+        "M  V30 31 1 26 33                                        \n"
+        "M  V30 32 1 26 34 CFG=1                                  \n"
+        "M  V30 33 1 25 35 CFG=3                                  \n"
+        "M  V30 34 1 24 36 CFG=1                                  \n"
+        "M  V30 35 1 33 37                                        \n"
+        "M  V30 END BOND                                          \n"
+        "M  V30 BEGIN COLLECTION                                  \n"
+        "M  V30 MDLV30/STERAC2 ATOMS=(2 1 19)                     \n"
+        "M  V30 MDLV30/STERAC1 ATOMS=(4 2 3 20 21)                \n"
+        "M  V30 MDLV30/STEABS ATOMS=(4 4 5 22 23)                 \n"
+        "M  V30 MDLV30/STEREL1 ATOMS=(4 12 13 24 25)              \n"
+        "M  V30 MDLV30/STEREL2 ATOMS=(2 14 26)                    \n"
+        "M  V30 END COLLECTION                                    \n"
+        "M  V30 END CTAB                                          \n"
+        "M  END                                                   \n";
+
+    char options[] = "-EnhancedStereochemistry";
+    inchi_Output output;
+    inchi_Output *poutput = &output;
+    const char expected_inchi[] = "InChI=1B/C11H16BrCl7.C10H14BrCl7/c1-3-5(13)7(15)9(17)11(19)10(18)8(16)6(14)4(2)12;1-3(11)5(13)7(15)9(17)10(18)8(16)6(14)4(2)12/h4-11H,3H2,1-2H3;3-10H,1-2H3/t4-,5-,6+,7-,8-,9-,10+,11-;3-,4-,5+,6-,7-,8-,9+,10-/m00/s1(4,6)2(5)(7,9)3(8,10)(11);1(3,5)2(4)(6,8)3(7,9)(10)";
+
+    EXPECT_EQ(MakeINCHIFromMolfileText(molblock, options, poutput), 0);
+    EXPECT_STREQ(poutput->szInChI, expected_inchi);
+
+    poutput->szLog = nullptr;
+    poutput->szMessage = nullptr;
+
+    FreeINCHI(poutput);
+}
+
+TEST(test_enhancedStereo, test_EnhancedStereochemistry_differing_AND_groups_of_same_molecule_1)
+{
+    const char *molblock1 =
+        "test mol                                     \n"
+        "  -INDIGO-02192610442D                       \n"
+        "                                             \n"
+        "  0  0  0  0  0  0  0  0  0  0  0 V3000      \n"
+        "M  V30 BEGIN CTAB                            \n"
+        "M  V30 COUNTS 7 6 0 0 0                      \n"
+        "M  V30 BEGIN ATOM                            \n"
+        "M  V30 1 O 1.54199 -5.725 0.0 0              \n"
+        "M  V30 2 C 2.40801 -5.225 0.0 0              \n"
+        "M  V30 3 C 3.27404 -5.725 0.0 0 CFG=1        \n"
+        "M  V30 4 C 4.14006 -5.225 0.0 0 CFG=2        \n"
+        "M  V30 5 C 5.00609 -5.725 0.0 0              \n"
+        "M  V30 6 Br 4.14006 -4.225 0.0 0             \n"
+        "M  V30 7 Cl 3.27404 -6.725 0.0 0             \n"
+        "M  V30 END ATOM                              \n"
+        "M  V30 BEGIN BOND                            \n"
+        "M  V30 1 1 1 2                               \n"
+        "M  V30 2 1 2 3                               \n"
+        "M  V30 3 1 3 4                               \n"
+        "M  V30 4 1 4 5                               \n"
+        "M  V30 5 1 4 6 CFG=1                         \n"
+        "M  V30 6 1 3 7 CFG=1                         \n"
+        "M  V30 END BOND                              \n"
+        "M  V30 BEGIN COLLECTION                      \n"
+        "M  V30 MDLV30/STERAC1 ATOMS=(1 3)            \n"
+        "M  V30 MDLV30/STERAC2 ATOMS=(1 4)            \n"
+        "M  V30 END COLLECTION                        \n"
+        "M  V30 END CTAB                              \n"
+        "M  END                                       \n";
+
+    const char *molblock2 =
+        "test mol                                 \n"
+        "  -INDIGO-02192610462D                   \n"
+        "                                         \n"
+        "  0  0  0  0  0  0  0  0  0  0  0 V3000  \n"
+        "M  V30 BEGIN CTAB                        \n"
+        "M  V30 COUNTS 7 6 0 0 0                  \n"
+        "M  V30 BEGIN ATOM                        \n"
+        "M  V30 1 O 1.54199 -5.725 0.0 0          \n"
+        "M  V30 2 C 2.40801 -5.225 0.0 0          \n"
+        "M  V30 3 C 3.27404 -5.725 0.0 0 CFG=1    \n"
+        "M  V30 4 C 4.14006 -5.225 0.0 0 CFG=2    \n"
+        "M  V30 5 C 5.00609 -5.725 0.0 0          \n"
+        "M  V30 6 Br 4.14006 -4.225 0.0 0         \n"
+        "M  V30 7 Cl 3.27404 -6.725 0.0 0         \n"
+        "M  V30 END ATOM                          \n"
+        "M  V30 BEGIN BOND                        \n"
+        "M  V30 1 1 1 2                           \n"
+        "M  V30 2 1 2 3                           \n"
+        "M  V30 3 1 3 4                           \n"
+        "M  V30 4 1 4 5                           \n"
+        "M  V30 5 1 4 6 CFG=1                     \n"
+        "M  V30 6 1 3 7 CFG=1                     \n"
+        "M  V30 END BOND                          \n"
+        "M  V30 BEGIN COLLECTION                  \n"
+        "M  V30 MDLV30/STERAC2 ATOMS=(1 3)        \n"
+        "M  V30 MDLV30/STERAC1 ATOMS=(1 4)        \n"
+        "M  V30 END COLLECTION                    \n"
+        "M  V30 END CTAB                          \n"
+        "M  END                                   \n";
+
+    char options[] = "-EnhancedStereochemistry";
+    const char expected_inchi[] = "InChI=1B/C4H8BrClO/c1-3(5)4(6)2-7/h3-4,7H,2H2,1H3/t3-,4-/m0/s3(3)(4)";
+
+    inchi_Output output1;
+    inchi_Output *poutput1 = &output1;
+    EXPECT_EQ(MakeINCHIFromMolfileText(molblock1, options, poutput1), 0);
+    EXPECT_STREQ(poutput1->szInChI, expected_inchi);
+
+    inchi_Output output2;
+    inchi_Output *poutput2 = &output2;
+    EXPECT_EQ(MakeINCHIFromMolfileText(molblock2, options, poutput2), 0);
+    EXPECT_STREQ(poutput2->szInChI, expected_inchi);
+
+    poutput1->szLog = nullptr;
+    poutput1->szMessage = nullptr;
+    FreeINCHI(poutput1);
+
+    poutput2->szLog = nullptr;
+    poutput2->szMessage = nullptr;
+    FreeINCHI(poutput2);
+}
+
+TEST(test_enhancedStereo, test_EnhancedStereochemistry_differing_AND_groups_of_same_molecule_2)
+{
+    const char *molblock =
+        "test_mol                                  \n"
+        "  -INDIGO-02192611042D                    \n"
+        "                                          \n"
+        "  0  0  0  0  0  0  0  0  0  0  0 V3000   \n"
+        "M  V30 BEGIN CTAB                         \n"
+        "M  V30 COUNTS 14 12 0 0 0                 \n"
+        "M  V30 BEGIN ATOM                         \n"
+        "M  V30 1 O 4.21699 -6.575 0.0 0           \n"
+        "M  V30 2 C 5.08301 -6.075 0.0 0           \n"
+        "M  V30 3 C 5.94904 -6.575 0.0 0 CFG=1     \n"
+        "M  V30 4 C 6.81506 -6.075 0.0 0 CFG=2     \n"
+        "M  V30 5 C 7.68109 -6.575 0.0 0           \n"
+        "M  V30 6 Br 6.81506 -5.075 0.0 0          \n"
+        "M  V30 7 Cl 5.94904 -7.575 0.0 0          \n"
+        "M  V30 8 O 11.2179 -6.4 0.0 0             \n"
+        "M  V30 9 C 12.084 -5.9 0.0 0              \n"
+        "M  V30 10 C 12.95 -6.4 0.0 0 CFG=1        \n"
+        "M  V30 11 C 13.816 -5.9 0.0 0 CFG=2       \n"
+        "M  V30 12 C 14.6821 -6.4 0.0 0            \n"
+        "M  V30 13 Br 13.816 -4.9 0.0 0            \n"
+        "M  V30 14 Cl 12.95 -7.4 0.0 0             \n"
+        "M  V30 END ATOM                           \n"
+        "M  V30 BEGIN BOND                         \n"
+        "M  V30 1 1 1 2                            \n"
+        "M  V30 2 1 2 3                            \n"
+        "M  V30 3 1 3 4                            \n"
+        "M  V30 4 1 4 5                            \n"
+        "M  V30 5 1 4 6 CFG=1                      \n"
+        "M  V30 6 1 3 7 CFG=1                      \n"
+        "M  V30 7 1 8 9                            \n"
+        "M  V30 8 1 9 10                           \n"
+        "M  V30 9 1 10 11                          \n"
+        "M  V30 10 1 11 12                         \n"
+        "M  V30 11 1 11 13 CFG=1                   \n"
+        "M  V30 12 1 10 14 CFG=1                   \n"
+        "M  V30 END BOND                           \n"
+        "M  V30 BEGIN COLLECTION                   \n"
+        "M  V30 MDLV30/STERAC2 ATOMS=(1 3)         \n"
+        "M  V30 MDLV30/STERAC1 ATOMS=(1 4)         \n"
+        "M  V30 MDLV30/STERAC3 ATOMS=(1 10)        \n"
+        "M  V30 MDLV30/STERAC4 ATOMS=(1 11)        \n"
+        "M  V30 END COLLECTION                     \n"
+        "M  V30 END CTAB                           \n"
+        "M  END                                    \n";
+
+    char options[] = "-EnhancedStereochemistry";
+    inchi_Output output;
+    inchi_Output *poutput = &output;
+    const char expected_inchi[] = "InChI=1B/2C4H8BrClO/c2*1-3(5)4(6)2-7/h2*3-4,7H,2H2,1H3/t2*3-,4-/m00/s2*3(3)(4)";
+
+    EXPECT_EQ(MakeINCHIFromMolfileText(molblock, options, poutput), 0);
+    EXPECT_STREQ(poutput->szInChI, expected_inchi);
+
+    poutput->szLog = nullptr;
+    poutput->szMessage = nullptr;
+
+    FreeINCHI(poutput);
+}
+
+TEST(test_enhancedStereo, test_EnhancedStereochemistry_test_file_1)
+{
+
+    const char* inchi_filename = "../../../../../INCHI-1-TEST/tests/test_unit/fixtures/enh_stereo_test_file_1.sdf";
+    // const char* inchi_filename = "/workspaces/InChI/INCHI-1-TEST/tests/test_unit/fixtures/enh_stereo_test_file_1.sdf";
+
+    std::ifstream file_inchi(inchi_filename, std::ios::binary);
+    ASSERT_TRUE(file_inchi.is_open());
+
+    // Read the whole file into a string
+    std::stringstream buffer;
+    buffer << file_inchi.rdbuf();
+    std::string file_content = buffer.str();
+    file_inchi.close();
+
+    // Split on "$$$$"
+    std::vector<std::string> molblocks;
+    size_t pos = 0;
+    size_t prev = 0;
+    const std::string delimiter = "$$$$";
+    while ((pos = file_content.find(delimiter, prev)) != std::string::npos) {
+        std::string mol = file_content.substr(prev, pos - prev);
+        // Optionally trim whitespace
+        size_t first_non_ws = mol.find_first_not_of(" \t\r\n");
+        if (first_non_ws != std::string::npos) {
+            mol = mol.substr(first_non_ws);
+            molblocks.push_back(mol);
+        }
+        prev = pos + delimiter.length();
+    }
+    // Add the last block if any
+    std::string mol = file_content.substr(prev);
+    size_t first_non_ws = mol.find_first_not_of(" \t\r\n");
+    if (first_non_ws != std::string::npos) {
+        mol = mol.substr(first_non_ws);
+        molblocks.push_back(mol);
+    }
+
+    std::vector<std::string> list_expected_inchis = {
+        "InChI=1B/C5H13NO/c1-3-5(6)4(2)7/h4-5,7H,3,6H2,1-2H3/t4-,5-/m1/s1",
+        "InChI=1B/C4H10O/c1-3-4(2)5/h4-5H,3H2,1-2H3/t4-/m0/s2(4)",
+        "InChI=1B/C5H13NO/c1-3-5(6)4(2)7/h4-5,7H,3,6H2,1-2H3/t4-,5-/m0/s2(4,5)",
+        "InChI=1B/C4H10O/c1-3-4(2)5/h4-5H,3H2,1-2H3/t4-/m1/s1",
+        "InChI=1B/C5H13NO/c1-3-5(6)4(2)7/h4-5,7H,3,6H2,1-2H3/t4-,5-/m0/s2(4)(5)",
+        "InChI=1B/C5H13NO/c1-3-5(6)4(2)7/h4-5,7H,3,6H2,1-2H3",
+        "InChI=1B/C5H13NO/c1-3-5(6)4(2)7/h4-5,7H,3,6H2,1-2H3/t4-,5-/m0/s3(4,5)",
+        "InChI=1B/C4H10O/c1-3-4(2)5/h4-5H,3H2,1-2H3/t4-/m0/s3(4)",
+        "InChI=1B/C4H10O/c1-3-4(2)5/h4-5H,3H2,1-2H3",
+        "InChI=1B/C5H13NO/c1-3-5(6)4(2)7/h4-5,7H,3,6H2,1-2H3/t4-,5-/m0/s3(4)(5)",
+        "InChI=1B/C6H12O3/c7-4-1-2-5(8)6(9)3-4/h4-9H,1-3H2/t4-,5+,6-/m0/s1(4,5)2(6)",
+        "InChI=1B/C6H12O3/c7-4-1-2-5(8)6(9)3-4/h4-9H,1-3H2/t4-,5+,6?/m0/s1",
+        "InChI=1B/C6H12O3/c7-4-1-2-5(8)6(9)3-4/h4-9H,1-3H2/t4-,5-,6+/m0/s1(4)2(5,6)",
+        "InChI=1B/C6H12O3/c7-4-1-2-5(8)6(9)3-4/h4-9H,1-3H2/t4-,5?,6?/m0/s1",
+        "InChI=1B/C6H12O3/c7-4-1-2-5(8)6(9)3-4/h4-9H,1-3H2/t4-,5-,6-/m0/s1(4)2(5,6)",
+        "InChI=1B/C7H17NO/c1-4-5(2)7(8)6(3)9/h5-7,9H,4,8H2,1-3H3/t5-,6-,7+/m1/s1(6)2(5,7)",
+        "InChI=1B/C7H17NO/c1-4-5(2)7(8)6(3)9/h5-7,9H,4,8H2,1-3H3/t5?,6-,7?/m1/s1",
+        "InChI=1B/C7H17NO/c1-4-5(2)7(8)6(3)9/h5-7,9H,4,8H2,1-3H3/t5-,6-,7-/m1/s1(6)2(5,7)",
+        "InChI=1B/C6H12O3/c7-4-1-2-5(8)6(9)3-4/h4-9H,1-3H2/t4-,5-,6-/m0/s1(4)2(5)(6)",
+        "InChI=1B/C5H13NO/c1-3-5(6)4(2)7/h4-5,7H,3,6H2,1-2H3/t4-,5-/m1/s1(4)3(5)",
+        "InChI=1B/C5H13NO/c1-3-5(6)4(2)7/h4-5,7H,3,6H2,1-2H3/t4-,5?/m0/s3(4)",
+        "InChI=1B/C6H12O3/c7-4-1-2-5(8)6(9)3-4/h4-9H,1-3H2/t4-,5-,6-/m0/s1(4)3(5,6)",
+        "InChI=1B/C6H12O3/c7-4-1-2-5(8)6(9)3-4/h4-9H,1-3H2/t4-,5-,6+/m0/s1(4)3(5,6)",
+        "InChI=1B/C6H12O3/c7-4-1-2-5(8)6(9)3-4/h4-9H,1-3H2/t4-,5?,6?/m0/s3(4)",
+        "InChI=1B/C7H17NO/c1-4-5(2)7(8)6(3)9/h5-7,9H,4,8H2,1-3H3/t5?,6-,7?/m0/s3(6)",
+        "InChI=1B/C7H17NO/c1-4-5(2)7(8)6(3)9/h5-7,9H,4,8H2,1-3H3/t5-,6-,7-/m1/s1(6)3(5,7)",
+        "InChI=1B/C7H17NO/c1-4-5(2)7(8)6(3)9/h5-7,9H,4,8H2,1-3H3/t5-,6-,7+/m1/s1(6)3(5,7)",
+        "InChI=1B/C6H12O3/c7-4-1-2-5(8)6(9)3-4/h4-9H,1-3H2/t4-,5-,6-/m0/s1(4)3(5)(6)",
+        "InChI=1B/C6H12O3/c7-4-1-2-5(8)6(9)3-4/h4-9H,1-3H2/t4-,5-,6-/m0/s1(4)2(5)3(6)",
+        "InChI=1B/C5H13NO/c1-3-5(6)4(2)7/h4-5,7H,3,6H2,1-2H3/t4-,5?/m1/s1",
+        "InChI=1B/C5H13NO/c1-3-5(6)4(2)7/h4-5,7H,3,6H2,1-2H3/t4-,5?/m0/s3(4)",
+        "InChI=1B/C5H13NO/c1-3-5(6)4(2)7/h4-5,7H,3,6H2,1-2H3/t4-,5?/m0/s2(4)",
+        "InChI=1B/C6H12O3/c7-4-1-2-5(8)6(9)3-4/h4-9H,1-3H2",
+    };
+
+    int nof_inchis = 33;
+
+    EXPECT_EQ(nof_inchis, molblocks.size());
+    EXPECT_EQ(nof_inchis, list_expected_inchis.size());
+
+    char options[] = "-EnhancedStereochemistry";
+
+    for (int i = 0; i < nof_inchis; ++i) {
+
+        inchi_Output output;
+        inchi_Output* poutput = &output;
+
+        poutput->szLog = nullptr;
+        poutput->szMessage = nullptr;
+        poutput->szInChI = nullptr;
+
+        int ret = MakeINCHIFromMolfileText(molblocks[i].c_str(), options, poutput);
+
+        EXPECT_LT(ret, 2);
+
+        EXPECT_STREQ(poutput->szInChI, list_expected_inchis[i].c_str());
+
+        if (poutput->szLog) {
+            inchi_free(poutput->szLog);
+            poutput->szLog = nullptr;
+        }
+        if (poutput->szMessage) {
+            inchi_free(poutput->szMessage);
+            poutput->szMessage = nullptr;
+        }
+        if (poutput->szInChI) {
+            inchi_free(poutput->szInChI);
+            poutput->szInChI = nullptr;
+        }
+    }
+}
diff --git a/INCHI-1-TEST/tests/test_unit/test_ichimain.cpp b/INCHI-1-TEST/tests/test_unit/test_ichimain.cpp
index 7b7458dd..9b1d09b0 100644
--- a/INCHI-1-TEST/tests/test_unit/test_ichimain.cpp
+++ b/INCHI-1-TEST/tests/test_unit/test_ichimain.cpp
@@ -191,7 +191,6 @@ TEST(test_ichimain, test_CalcAndPrintINCHIAndINCHIKEY) {
     PINChI_Aux2* pINChI_Aux[INCHI_NUM] = {};
     ORIG_ATOM_DATA prep_inp_data = {};
     INCHI_IOS_STRING *strbuf = new INCHI_IOS_STRING;
-    memset(strbuf, 0, sizeof(*strbuf));
     inchi_strbuf_init(strbuf, INCHI_STRBUF_INITIAL_SIZE, INCHI_STRBUF_SIZE_INCREMENT);
 
     unsigned long pulTotalProcessingTime = 0;
@@ -292,7 +291,8 @@ TEST(test_ichimain, test_ProcessMultipleInputFiles_2mol_files)
 
     char tmpl[] = "../../../../../INCHI-1-TEST/tests/test_unit/fixtures/inchi_mol_test_XXXXXX";
     char *tmpd = mkdtemp(tmpl);
-    ASSERT_NE(tmpd, nullptr);
+
+    EXPECT_NE(tmpd, nullptr);
 
     std::vector<std::string> dist_paths;
     for (auto cur_filename : input_mols) {
diff --git a/INCHI-1-TEST/tests/test_unit/test_ichimake.cpp b/INCHI-1-TEST/tests/test_unit/test_ichimake.cpp
new file mode 100644
index 00000000..94a2c69a
--- /dev/null
+++ b/INCHI-1-TEST/tests/test_unit/test_ichimake.cpp
@@ -0,0 +1,90 @@
+#include <gtest/gtest.h>
+#include <gmock/gmock.h>
+#include <unistd.h>
+#include <sys/stat.h>
+#include <fstream>
+#include <filesystem>
+#include <vector>
+
+extern "C"
+{
+#include "../../../INCHI-1-SRC/INCHI_BASE/src/ichimake.c"
+#include "../../../INCHI-1-SRC/INCHI_BASE/src/ichi_io.h"
+}
+
+TEST(test_ichimake, test_GetSp3RelRacAbs_none)
+{
+
+    INChI inchi = {0};
+    INChI_Stereo stereo = {0};
+
+    stereo.nNumberOfStereoCenters = 0;
+
+    // pINChI->bDeleted
+    // Stereo->nCompInv2Abs
+    // 0: No inversion (structure unchanged by inversion)
+    // Positive integer (>0): Indicates inversion changes the structure (normal/absolute stereo)
+    // Negative integer (<0): Indicates inversion changes the structure (inverted/absolute stereo)
+
+    //int GetSp3RelRacAbs(const INChI* pINChI, INChI_Stereo* Stereo);
+
+    int result = GetSp3RelRacAbs(&inchi, &stereo);
+
+    EXPECT_EQ(result, SP3_NONE);
+
+}
+
+TEST(test_ichimake, test_GetSp3RelRacAbs_sp3)
+{
+    INChI inchi = {0};
+    INChI_Stereo stereo = {0};
+
+    stereo.nNumberOfStereoCenters = 1;
+    stereo.nCompInv2Abs = 0;
+
+    int result = GetSp3RelRacAbs(&inchi, &stereo);
+
+    EXPECT_EQ(result, SP3_ONLY);
+}
+
+TEST(test_ichimake, test_GetSp3RelRacAbs_rel)
+{
+    INChI inchi = {0};
+    INChI_Stereo stereo = {0};
+
+    inchi.nFlags = INCHI_FLAG_REL_STEREO;
+    stereo.nNumberOfStereoCenters = 1;
+    stereo.nCompInv2Abs = 1;
+
+    int result = GetSp3RelRacAbs(&inchi, &stereo);
+
+    EXPECT_EQ(result, SP3_REL);
+}
+
+TEST(test_ichimake, test_GetSp3RelRacAbs_rac)
+{
+    INChI inchi = {0};
+    INChI_Stereo stereo = {0};
+
+    inchi.nFlags = INCHI_FLAG_RAC_STEREO;
+    stereo.nNumberOfStereoCenters = 1;
+    stereo.nCompInv2Abs = 1;
+
+    int result = GetSp3RelRacAbs(&inchi, &stereo);
+
+    EXPECT_EQ(result, SP3_RAC);
+}
+
+TEST(test_ichimake, test_GetSp3RelRacAbs_abs)
+{
+    INChI inchi = {0};
+    INChI_Stereo stereo = {0};
+
+    inchi.nFlags = 0x0111;
+    stereo.nNumberOfStereoCenters = 1;
+    stereo.nCompInv2Abs = 1;
+
+    int result = GetSp3RelRacAbs(&inchi, &stereo);
+
+    EXPECT_EQ(result, SP3_ABS);
+}
diff --git a/INCHI-1-TEST/tests/test_unit/test_ichiprt1.cpp b/INCHI-1-TEST/tests/test_unit/test_ichiprt1.cpp
new file mode 100644
index 00000000..67b5aefc
--- /dev/null
+++ b/INCHI-1-TEST/tests/test_unit/test_ichiprt1.cpp
@@ -0,0 +1,594 @@
+#include <gtest/gtest.h>
+#include <gmock/gmock.h>
+#include <unistd.h>
+#include <sys/stat.h>
+#include <fstream>
+#include <filesystem>
+#include <vector>
+
+extern "C"
+{
+#include "../../../INCHI-1-SRC/INCHI_BASE/src/ichi_io.h"
+#include "../../../INCHI-1-SRC/INCHI_BASE/src/ichiprt1.c"
+#include "../../../INCHI-1-SRC/INCHI_BASE/src/strutil.c"
+#include "../../../INCHI-1-SRC/INCHI_BASE/src/ichimake.h"
+#include "../../../INCHI-1-SRC/INCHI_BASE/src/ichicano.h"
+}
+
+
+TEST(test_ichiprt1, test_OutputINCHI_StereoLayer)
+{
+
+    CANON_GLOBALS cg = {0};
+    INCHI_IOSTREAM out_file = {0};
+    INCHI_IOS_STRING strbuf = {0};
+    INCHI_OUT_CTL io = {0};
+    char lf[] = "\n";
+    char tab[] = "\t";
+
+    inchi_strbuf_init(&strbuf, INCHI_STRBUF_INITIAL_SIZE, INCHI_STRBUF_SIZE_INCREMENT);
+    inchi_ios_init(&out_file, INCHI_IOS_TYPE_STRING, nullptr);
+
+    // int OutputINCHI_StereoLayer( CANON_GLOBALS    *pCG,
+    //                             INCHI_IOSTREAM   *out_file,
+    //                             INCHI_IOS_STRING *strbuf,
+    //                             INCHI_OUT_CTL    *io,
+    //                             char             *pLF,
+    //                             char             *pTAB )
+
+    int ret = OutputINCHI_StereoLayer(&cg, &out_file, &strbuf, &io, lf, tab);
+
+    EXPECT_EQ(ret, 0);
+
+    // Clean up
+    inchi_strbuf_close(&strbuf);
+
+}
+
+TEST(test_ichiprt1, test_OutputINCHI_StereoLayer_b_1)
+{
+    int num_at = 2;
+    int found_num_bonds = 0;
+    int found_num_isotopic = 0;
+
+    CANON_GLOBALS cg = {0};
+    INCHI_IOSTREAM out_file = {0};
+    INCHI_IOS_STRING strbuf = {0};
+    INCHI_OUT_CTL io = {0};
+    INCHI_SORT inchi_sort = {0};
+    inp_ATOM *atoms = CreateInpAtom(num_at);
+
+    atoms[0].valence = 1;
+    // atoms[0].el_number = (U_CHAR)get_periodic_table_number("C");
+    // atoms[0].orig_at_number = 4;
+    // atoms[0].neighbor[0] = 3;
+    // atoms[0].bond_type[0] = 2;
+
+    atoms[1].valence = 1;
+    // atoms[1].el_number = (U_CHAR)get_periodic_table_number("C");
+    // atoms[1].orig_at_number = 3;
+    // atoms[1].neighbor[0] = 4;
+    // atoms[1].bond_type[0] = 2;
+
+    INChI *inchi = Alloc_INChI(atoms, num_at, &found_num_bonds, &found_num_isotopic, 0);
+
+    inchi->nNumberOfAtoms = num_at;
+
+    int bond_atom1[1] = {4};
+    int bond_atom2[1] = {3};
+    S_CHAR b_parity[1] = {1}; // 1 = -, 2 = +
+
+    for (int i = 0; i < found_num_bonds; i++) {
+        inchi->Stereo->nBondAtom1[i] = bond_atom1[i];
+        inchi->Stereo->nBondAtom2[i] = bond_atom2[i];
+        inchi->Stereo->b_parity[i] = b_parity[i];
+    }
+
+    // inchi->Stereo->nCompInv2Abs = 1;
+    inchi->Stereo->nNumberOfStereoBonds = 1;
+    // inchi->Stereo->nNumberOfStereoCenters = 0;
+
+    inchi_sort.pINChI[0] = inchi;
+
+    io.pINChISort = &inchi_sort;
+    io.num_components = 1;
+
+    // io.bRelativeStereo[0] = 0;
+    // io.bRacemicStereo[0] = 0;
+
+    io.sDifSegs[0][DIFS_b_SBONDS] = DIFV_OUTPUT_FILL_T; // b
+    // io.sDifSegs[0][DIFS_t_SATOMS] = DIFV_OUTPUT_FILL_T; // t
+    // io.sDifSegs[0][DIFS_m_SP3INV] = DIFV_OUTPUT_FILL_T; // m
+    // io.sDifSegs[0][DIFS_s_STYPE] = DIFV_OUTPUT_FILL_T;  // s
+    io.nCurINChISegment = 0;
+    io.iCurTautMode = 0;
+    io.bPlainTextTags = 2;
+    io.nTag = 2;
+    io.bTag1 = IL_STER;
+    io.bTag2 = IL_STER | IL_TYPS;
+    io.bOutType = OUT_TN;
+
+    inchi_strbuf_init(&strbuf, INCHI_STRBUF_INITIAL_SIZE, INCHI_STRBUF_SIZE_INCREMENT);
+    inchi_ios_init(&out_file, INCHI_IOS_TYPE_STRING, nullptr);
+
+    int ret = OutputINCHI_StereoLayer(&cg, &out_file, &strbuf, &io, (char*)"", (char*)"");
+
+    EXPECT_EQ(std::string(out_file.s.pStr), "/b4-3-");
+    EXPECT_EQ(ret, 0);
+
+    inchi_strbuf_close(&strbuf);
+    inchi_ios_close(&out_file);
+
+    FreeInpAtom(&atoms);
+    Free_INChI(&inchi);
+}
+
+TEST(test_ichiprt1, test_OutputINCHI_StereoLayer_m0)
+{
+    CANON_GLOBALS cg = {0};
+    INCHI_IOSTREAM out_file = {0};
+    INCHI_IOS_STRING strbuf = {0};
+    INCHI_OUT_CTL io = {0};
+
+    io.sDifSegs[0][DIFS_m_SP3INV] = DIFV_OUTPUT_FILL_T;
+
+    io.nCurINChISegment = 0;
+    io.iCurTautMode = 0;
+    io.bPlainTextTags = 1;
+    io.bRelativeStereo[0] = 0;
+    io.bRacemicStereo[0] = 0;
+    io.bAlways = 0;
+    io.nTag = 2; // plain text
+    io.bTag1 = IL_STER;
+    io.bTag2 = IL_STER | IL_TYPS;
+    io.bOverflow = 0;
+    io.bOutType = OUT_TN;
+    io.num_components = 1;
+
+    inchi_strbuf_init(&strbuf, INCHI_STRBUF_INITIAL_SIZE, INCHI_STRBUF_SIZE_INCREMENT);
+    inchi_ios_init(&out_file, INCHI_IOS_TYPE_STRING, nullptr);
+
+    int num_at = 2;
+
+    int found_num_bonds = 0;
+    int found_num_isotopic = 0;
+    inp_ATOM *at = CreateInpAtom(num_at);
+    INChI *inchi = Alloc_INChI(at, num_at, &found_num_bonds, &found_num_isotopic, 0);
+    inchi->Stereo->nCompInv2Abs = 1;
+    inchi->nNumberOfAtoms = num_at;
+
+    INCHI_SORT *inchi_sort = (INCHI_SORT*)calloc(1, sizeof(INCHI_SORT));
+    inchi_sort->pINChI[TAUT_YES] = inchi;
+
+    io.pINChISort = inchi_sort;
+
+    int ret = OutputINCHI_StereoLayer(&cg, &out_file, &strbuf, &io, (char*)"", (char*)"");
+
+    EXPECT_EQ(std::string(strbuf.pStr), "/m0");
+    EXPECT_EQ(ret, 0);
+
+    inchi_strbuf_close(&strbuf);
+    inchi_ios_close(&out_file);
+
+    Free_INChI( &inchi );
+
+    FreeInpAtom(&at);
+
+    free(inchi_sort);
+}
+
+TEST(test_ichiprt1, test_OutputINCHI_StereoLayer_m1)
+{
+    CANON_GLOBALS cg = {0};
+    INCHI_IOSTREAM out_file = {0};
+    INCHI_IOS_STRING strbuf = {0};
+    INCHI_OUT_CTL io = {0};
+
+    io.sDifSegs[0][DIFS_m_SP3INV] = DIFV_OUTPUT_FILL_T;
+
+    io.nCurINChISegment = 0;
+    io.iCurTautMode = 0;
+    io.bPlainTextTags = 1;
+    io.bRelativeStereo[0] = 0;
+    io.bRacemicStereo[0] = 0;
+    io.bAlways = 0;
+    io.nTag = 2; // plain text
+    io.bTag1 = IL_STER;
+    io.bTag2 = IL_STER | IL_TYPS;
+    io.bOverflow = 0;
+    io.bOutType = OUT_TN;
+    io.num_components = 1;
+
+    inchi_strbuf_init(&strbuf, INCHI_STRBUF_INITIAL_SIZE, INCHI_STRBUF_SIZE_INCREMENT);
+    inchi_ios_init(&out_file, INCHI_IOS_TYPE_STRING, nullptr);
+
+    int num_at = 2;
+
+    int found_num_bonds = 0;
+    int found_num_isotopic = 0;
+    inp_ATOM *at = CreateInpAtom(num_at);
+    INChI *inchi = Alloc_INChI(at, num_at, &found_num_bonds, &found_num_isotopic, 0);
+    inchi->Stereo->nCompInv2Abs = -1;
+    inchi->nNumberOfAtoms = num_at;
+
+    INCHI_SORT *inchi_sort = (INCHI_SORT*)calloc(1, sizeof(INCHI_SORT));
+    inchi_sort->pINChI[TAUT_YES] = inchi;
+
+    io.pINChISort = inchi_sort;
+
+    int ret = OutputINCHI_StereoLayer(&cg, &out_file, &strbuf, &io, (char*)"", (char*)"");
+
+    EXPECT_EQ(std::string(strbuf.pStr), "/m1");
+    EXPECT_EQ(ret, 0);
+
+    inchi_strbuf_close(&strbuf);
+    inchi_ios_close(&out_file);
+
+    Free_INChI( &inchi );
+
+    FreeInpAtom(&at);
+
+    free(inchi_sort);
+}
+
+TEST(test_ichiprt1, test_OutputINCHI_StereoLayer_s1)
+{
+    CANON_GLOBALS cg = {0};
+    INCHI_IOSTREAM out_file = {0};
+    INCHI_IOS_STRING strbuf = {0};
+    INCHI_OUT_CTL io = {0};
+
+    io.sDifSegs[0][DIFS_s_STYPE] = DIFV_OUTPUT_FILL_T;
+
+    io.nCurINChISegment = 0;
+    io.iCurTautMode = 0;
+    io.bPlainTextTags = 1;
+    io.bRelativeStereo[0] = 0;
+    io.bRacemicStereo[0] = 0;
+    io.bAlways = 0;
+    io.nTag = 2; // plain text
+    io.bTag1 = IL_STER;
+    io.bTag2 = IL_STER | IL_TYPS;
+
+    inchi_strbuf_init(&strbuf, INCHI_STRBUF_INITIAL_SIZE, INCHI_STRBUF_SIZE_INCREMENT);
+    inchi_ios_init(&out_file, INCHI_IOS_TYPE_STRING, nullptr);
+
+    int ret = OutputINCHI_StereoLayer(&cg, &out_file, &strbuf, &io, (char*)"", (char*)"");
+
+    EXPECT_EQ(std::string(strbuf.pStr), "/s1");
+    EXPECT_EQ(ret, 0);
+
+    inchi_strbuf_close(&strbuf);
+    inchi_ios_close(&out_file);
+}
+
+TEST(test_ichiprt1, test_OutputINCHI_StereoLayer_s2)
+{
+    CANON_GLOBALS cg = {0};
+    INCHI_IOSTREAM out_file = {0};
+    INCHI_IOS_STRING strbuf = {0};
+    INCHI_OUT_CTL io = {0};
+
+    io.sDifSegs[0][DIFS_s_STYPE] = DIFV_OUTPUT_FILL_T;
+
+    io.nCurINChISegment = 0;
+    io.iCurTautMode = 0;
+    io.bPlainTextTags = 1;
+    io.bRelativeStereo[0] = 1;
+    io.bRacemicStereo[0] = 0;
+    io.bAlways = 0;
+    io.nTag = 2; // plain text
+    io.bTag1 = IL_STER;
+    io.bTag2 = IL_STER | IL_TYPS;
+
+    inchi_strbuf_init(&strbuf, INCHI_STRBUF_INITIAL_SIZE, INCHI_STRBUF_SIZE_INCREMENT);
+    inchi_ios_init(&out_file, INCHI_IOS_TYPE_STRING, nullptr);
+
+    int ret = OutputINCHI_StereoLayer(&cg, &out_file, &strbuf, &io, (char*)"", (char*)"");
+
+    EXPECT_EQ(std::string(strbuf.pStr), "/s2");
+    EXPECT_EQ(ret, 0);
+
+    inchi_strbuf_close(&strbuf);
+    inchi_ios_close(&out_file);
+}
+
+TEST(test_ichiprt1, test_OutputINCHI_StereoLayer_s3)
+{
+    CANON_GLOBALS cg = {0};
+    INCHI_IOSTREAM out_file = {0};
+    INCHI_IOS_STRING strbuf = {0};
+    INCHI_OUT_CTL io = {0};
+
+
+    io.sDifSegs[0][DIFS_s_STYPE] = DIFV_OUTPUT_FILL_T;
+    io.nCurINChISegment = 0;
+    io.iCurTautMode = 0;
+    io.bPlainTextTags = 1;
+    io.bRelativeStereo[0] = 0;
+    io.bRacemicStereo[0] = 1;
+    io.bAlways = 0;
+    io.nTag = 2; // plain text
+    io.bTag1 = IL_STER;
+    io.bTag2 = IL_STER | IL_TYPS;
+
+    inchi_strbuf_init(&strbuf, INCHI_STRBUF_INITIAL_SIZE, INCHI_STRBUF_SIZE_INCREMENT);
+    inchi_ios_init(&out_file, INCHI_IOS_TYPE_STRING, nullptr);
+
+    int ret = OutputINCHI_StereoLayer(&cg, &out_file, &strbuf, &io, (char*)"", (char*)"");
+
+    EXPECT_EQ(std::string(strbuf.pStr), "/s3");
+    EXPECT_EQ(ret, 0);
+
+    inchi_strbuf_close(&strbuf);
+    inchi_ios_close(&out_file);
+
+}
+
+TEST(test_ichiprt1, test_OutputINCHI_StereoLayer_layers_t)
+{
+
+    int num_at = 8;
+    int found_num_bonds = 0;
+    int found_num_isotopic = 0;
+
+    CANON_GLOBALS cg = {0};
+    INCHI_IOSTREAM out_file = {0};
+    INCHI_IOS_STRING strbuf = {0};
+    INCHI_OUT_CTL io = {0};
+    INCHI_SORT inchi_sort = {0};
+    AT_NUMB numbers[8] = {3,4,5,6,7,8,9,10};
+    S_CHAR parities[8] = {1,1,2,2,1,2,2,1};// -,-,+,+,-,+,+,-
+    inp_ATOM *at = CreateInpAtom(num_at);
+    INChI *inchi = Alloc_INChI(at, num_at, &found_num_bonds, &found_num_isotopic, 0);
+
+    inchi->nNumberOfAtoms = num_at;
+    inchi->Stereo->nCompInv2Abs = 1;
+    inchi->Stereo->nNumberOfStereoBonds = 0;
+    inchi->Stereo->nNumberOfStereoCenters = num_at;
+
+    for (int i = 0; i < num_at; i++) {
+        inchi->Stereo->nNumber[i] = numbers[i];
+        inchi->Stereo->t_parity[i] = parities[i];
+    }
+
+    inchi_sort.pINChI[0] = inchi;
+
+    io.pINChISort = &inchi_sort;
+    io.num_components = 1;
+    io.bRelativeStereo[0] = 0;
+    io.bRacemicStereo[0] = 1;
+    // io.sDifSegs[0][DIFS_b_SBONDS] = DIFV_OUTPUT_FILL_T; // b
+    io.sDifSegs[0][DIFS_t_SATOMS] = DIFV_OUTPUT_FILL_T; // t
+    // io.sDifSegs[0][DIFS_m_SP3INV] = DIFV_OUTPUT_FILL_T; // m
+    // io.sDifSegs[0][DIFS_s_STYPE] = DIFV_OUTPUT_FILL_T;  // s
+    io.nCurINChISegment = 0;
+    io.iCurTautMode = 0;
+    io.bPlainTextTags = 2; /* 0 => no plain tags, 1=> plain text tags, 2=>plaintext tags without consecutive // */
+    io.nTag = 2;
+    io.bTag1 = IL_STER;
+    io.bTag2 = IL_STER | IL_TYPS;
+    io.bOutType = OUT_TN;
+
+    inchi_strbuf_init(&strbuf, INCHI_STRBUF_INITIAL_SIZE, INCHI_STRBUF_SIZE_INCREMENT);
+    inchi_ios_init(&out_file, INCHI_IOS_TYPE_STRING, nullptr);
+
+    int ret = OutputINCHI_StereoLayer(&cg, &out_file, &strbuf, &io, (char*)"", (char*)"");
+
+    EXPECT_EQ(std::string(out_file.s.pStr), "/t3-,4-,5+,6+,7-,8+,9+,10-");
+    EXPECT_EQ(ret, 0);
+
+    inchi_strbuf_close(&strbuf);
+    inchi_ios_close(&out_file);
+
+    FreeInpAtom(&at);
+    Free_INChI(&inchi);
+}
+
+TEST(test_ichiprt1, test_OutputINCHI_StereoLayer_layers_t_m_s)
+{
+
+    int num_at = 8;
+    int found_num_bonds = 0;
+    int found_num_isotopic = 0;
+
+    CANON_GLOBALS cg = {0};
+    INCHI_IOSTREAM out_file = {0};
+    INCHI_IOS_STRING strbuf = {0};
+    INCHI_OUT_CTL io = {0};
+    INCHI_SORT inchi_sort = {0};
+    AT_NUMB numbers[8] = {3,4,5,6,7,8,9,10};
+    S_CHAR parities[8] = {1,1,2,2,1,2,2,1};// -,-,+,+,-,+,+,-
+    inp_ATOM *at = CreateInpAtom(num_at);
+    INChI *inchi = Alloc_INChI(at, num_at, &found_num_bonds, &found_num_isotopic, 0);
+
+    inchi->nNumberOfAtoms = num_at;
+    inchi->Stereo->nCompInv2Abs = 1;
+    inchi->Stereo->nNumberOfStereoBonds = 0;
+    inchi->Stereo->nNumberOfStereoCenters = num_at;
+
+    for (int i = 0; i < num_at; i++) {
+        inchi->Stereo->nNumber[i] = numbers[i];
+        inchi->Stereo->t_parity[i] = parities[i];
+    }
+
+    inchi_sort.pINChI[0] = inchi;
+
+    io.pINChISort = &inchi_sort;
+    io.num_components = 1;
+    io.bRelativeStereo[0] = 0;
+    io.bRacemicStereo[0] = 1;
+    io.sDifSegs[0][DIFS_b_SBONDS] = DIFV_OUTPUT_FILL_T; // b
+    io.sDifSegs[0][DIFS_t_SATOMS] = DIFV_OUTPUT_FILL_T; // t
+    io.sDifSegs[0][DIFS_m_SP3INV] = DIFV_OUTPUT_FILL_T; // m
+    io.sDifSegs[0][DIFS_s_STYPE] = DIFV_OUTPUT_FILL_T;  // s
+    io.nCurINChISegment = 0;
+    io.iCurTautMode = 0;
+    io.bPlainTextTags = 2; /* 0 => no plain tags, 1=> plain text tags, 2=>plaintext tags without consecutive // */
+    io.nTag = 2;
+    io.bTag1 = IL_STER;
+    io.bTag2 = IL_STER | IL_TYPS;
+    io.bOutType = OUT_TN;
+
+    inchi_strbuf_init(&strbuf, INCHI_STRBUF_INITIAL_SIZE, INCHI_STRBUF_SIZE_INCREMENT);
+    inchi_ios_init(&out_file, INCHI_IOS_TYPE_STRING, nullptr);
+
+    int ret = OutputINCHI_StereoLayer(&cg, &out_file, &strbuf, &io, (char*)"", (char*)"");
+
+    EXPECT_EQ(std::string(out_file.s.pStr), "/t3-,4-,5+,6+,7-,8+,9+,10-/m0/s3");
+    EXPECT_EQ(ret, 0);
+
+    inchi_strbuf_close(&strbuf);
+    inchi_ios_close(&out_file);
+
+    FreeInpAtom(&at);
+    Free_INChI(&inchi);
+}
+
+TEST(test_ichiprt1, test_set_line_separators)
+{
+
+    // void set_line_separators( int bINChIOutputOptions, char **pLF, char **pTAB )
+
+    char *lf = nullptr;
+    char *tab = nullptr;
+
+    // Plain text comments option
+    set_line_separators(INCHI_OUT_PLAIN_TEXT_COMMENTS, &lf, &tab);
+    EXPECT_STREQ(lf, "\n");
+    EXPECT_STREQ(tab, "\n");
+
+    // Tabbed output option
+    set_line_separators(INCHI_OUT_PLAIN_TEXT | INCHI_OUT_TABBED_OUTPUT, &lf, &tab);
+    EXPECT_STREQ(lf, "\0");
+    EXPECT_STREQ(tab, "\t");
+
+    // Plain text only
+    set_line_separators(INCHI_OUT_PLAIN_TEXT, &lf, &tab);
+    EXPECT_STREQ(lf, "\0");
+    EXPECT_STREQ(tab, "\n");
+
+    // No options
+    set_line_separators(0, &lf, &tab);
+    EXPECT_STREQ(lf, "\0");
+    EXPECT_STREQ(tab, "\n");
+
+
+}
+
+TEST(test_ichiprt1, test_szGetTag_basic)
+{
+
+    // nTag = 1: XML label (szXmlLabel)
+    // nTag = 2: Plain text label (szPlainLabel)
+    // nTag = 3: Plain label with comments (sometimes)
+
+    // bTag: A bitmask indicating which tag (or tags) to look up in the INCHI_TAG array.
+
+    char szTag[64] = {0};
+    int bAlways = -1;
+
+    EXPECT_STREQ(szGetTag(IdentLbl, 0, 0, szTag, &bAlways, 0), "???"); //fixed-H
+    EXPECT_STREQ(szTag, "???");
+
+}
+
+TEST(test_ichiprt1, test_szGetTag_returns_unknown_for_invalid_index)
+{
+    char szTag[64] = {0};
+    int bAlways = -1;
+    // nTag = 0, bTag = 0, should return "???"
+    EXPECT_STREQ(szGetTag(IdentLbl, 0, 0, szTag, &bAlways, 0), "???");
+    EXPECT_STREQ(szTag, "???");
+}
+
+TEST(test_ichiprt1, test_szGetTag_stereo_1)
+{
+    char szTag[64] = {0};
+    int bAlways = -1;
+    // nTag = 2 (plain text), bTag = IL_STER (stereo)
+    EXPECT_STREQ(szGetTag(IdentLbl, 2, IL_STER, szTag, &bAlways, 0), "/");
+    EXPECT_STREQ(szTag, "/");
+}
+
+TEST(test_ichiprt1, test_szGetTag_stereo_2)
+{
+    char szTag[64] = {0};
+    int bAlways = -1;
+    // nTag = 2 (plain text), bTag = IL_STER (stereo)
+    EXPECT_STREQ(szGetTag(IdentLbl, 1, IL_STER, szTag, &bAlways, 0), "stereo");
+    EXPECT_STREQ(szTag, "stereo");
+}
+
+TEST(test_ichiprt1, test_szGetTag_stereo_3)
+{
+    char szTag[64] = {0};
+    int bAlways = -1;
+    // nTag = 2 (plain text), bTag = IL_STER (stereo)
+    EXPECT_STREQ(szGetTag(IdentLbl, 2, IL_SP3S, szTag, &bAlways, 0), "/t");
+    EXPECT_STREQ(szTag, "/t");
+}
+
+TEST(test_ichiprt1, test_szGetTag_stereo_4)
+{
+    char szTag[64] = {0};
+    int bAlways = -1;
+    // nTag = 2 (plain text), bTag = IL_STER (stereo)
+    EXPECT_STREQ(szGetTag(IdentLbl, 2, IL_INVS, szTag, &bAlways, 0), "/m");
+    EXPECT_STREQ(szTag, "/m");
+}
+
+TEST(test_ichiprt1, test_szGetTag_stereo_5)
+{
+    char szTag[64] = {0};
+    int bAlways = -1;
+    // nTag = 2 (plain text), bTag = IL_STER (stereo)
+    EXPECT_STREQ(szGetTag(IdentLbl, 2, IL_TYPS, szTag, &bAlways, 0), "/s");
+    EXPECT_STREQ(szTag, "/s");
+}
+
+TEST(test_ichiprt1, test_szGetTag_stereo_6)
+{
+    char szTag[64] = {0};
+    int bAlways = -1;
+    // nTag = 2 (plain text), bTag = IL_STER (stereo)
+    EXPECT_STREQ(szGetTag(IdentLbl, 1, IL_TYPS, szTag, &bAlways, 0), "type");
+    EXPECT_STREQ(szTag, "type");
+}
+
+TEST(test_ichiprt1, test_szGetTag_hfixed)
+{
+    char szTag[64] = {0};
+    int bAlways = -1;
+    // nTag = 2 (plain text), bTag = IL_STER (stereo)
+    EXPECT_STREQ(szGetTag(IdentLbl, 1, IL_FIXH, szTag, &bAlways, 0), "fixed-H");
+    EXPECT_STREQ(szTag, "fixed-H");
+}
+
+TEST(test_ichiprt1, test_szGetTag_returns_xml_label)
+{
+    char szTag[64] = {0};
+    int bAlways = -1;
+    // nTag = 1 (XML), bTag = IL_CONN (connections)
+    EXPECT_STREQ(szGetTag(IdentLbl, 1, IL_CONN, szTag, &bAlways, 0), "connections");
+    EXPECT_STREQ(szTag, "connections");
+}
+
+TEST(test_ichiprt1, test_szGetTag_sets_bAlways)
+{
+    char szTag[64] = {0};
+    int bAlways = -1;
+    // nTag = 2 (plain text), bTag = IL_FML_ (formula), which has bAlwaysOutput = 1
+    szGetTag(IdentLbl, 2, IL_FML_, szTag, &bAlways, 0);
+    EXPECT_EQ(bAlways, -1);
+    EXPECT_STREQ(szTag, "/");
+}
+
+TEST(test_ichiprt1, test_szGetTag_charge)
+{
+    char szTag[64] = {0};
+    int bAlways = -1;
+    // nTag = 2 (plain text), bTag = IL_CHRG (charge)
+    EXPECT_STREQ(szGetTag(IdentLbl, 2, IL_CHRG, szTag, &bAlways, 0), "/q");
+    EXPECT_STREQ(szTag, "/q");
+}
diff --git a/INCHI-1-TEST/tests/test_unit/test_ichiprt1_enhancedStereo.cpp b/INCHI-1-TEST/tests/test_unit/test_ichiprt1_enhancedStereo.cpp
new file mode 100644
index 00000000..7c5f7bef
--- /dev/null
+++ b/INCHI-1-TEST/tests/test_unit/test_ichiprt1_enhancedStereo.cpp
@@ -0,0 +1,157 @@
+#include <gtest/gtest.h>
+#include <gmock/gmock.h>
+#include <unistd.h>
+#include <sys/stat.h>
+#include <fstream>
+#include <filesystem>
+#include <vector>
+
+extern "C"
+{
+#include "../../../INCHI-1-SRC/INCHI_BASE/src/ichi_io.h"
+#include "../../../INCHI-1-SRC/INCHI_BASE/src/ichiprt1.c"
+#include "../../../INCHI-1-SRC/INCHI_BASE/src/strutil.c"
+#include "../../../INCHI-1-SRC/INCHI_BASE/src/ichimake.h"
+#include "../../../INCHI-1-SRC/INCHI_BASE/src/ichicano.h"
+}
+
+
+TEST(test_ichiprt1_enhancedStereo, test_OutputINCHI_StereoLayer_enhanced_stereo_1)
+{
+
+    CANON_GLOBALS cg = {0};
+    INCHI_IOSTREAM out_file = {0};
+    INCHI_IOS_STRING strbuf = {0};
+    INCHI_OUT_CTL io = {0};
+    ORIG_ATOM_DATA *oad;
+
+    oad = (ORIG_ATOM_DATA *)inchi_calloc(1, sizeof(ORIG_ATOM_DATA));
+    oad->v3000 = (OAD_V3000 *)inchi_calloc(1, sizeof(OAD_V3000));
+
+    oad->v3000->n_collections = 5;
+    oad->v3000->n_steabs = 1;
+
+    oad->v3000->lists_steabs = (int **)inchi_calloc(oad->v3000->n_steabs, sizeof(int*));
+    oad->v3000->lists_steabs[0] = (int *)inchi_calloc(2+2, sizeof(int));
+
+    // STEABS ATOMS=(2 4 5)
+    oad->v3000->lists_steabs[0][0] = 1; // - not used
+    oad->v3000->lists_steabs[0][1] = 2; // number of members in collection
+    oad->v3000->lists_steabs[0][2] = 4; //  member atom numbers
+    oad->v3000->lists_steabs[0][3] = 5; //  member atom numbers
+
+    // STERAC2 ATOMS=(1 1)
+    oad->v3000->n_sterac = 2;
+
+    oad->v3000->lists_sterac = (int **)inchi_calloc(oad->v3000->n_sterac, sizeof(int*));
+    oad->v3000->lists_sterac[0] = (int *)inchi_calloc(2 + 1, sizeof(int));
+    oad->v3000->lists_sterac[1] = (int *)inchi_calloc(2 + 2, sizeof(int));
+
+    oad->v3000->lists_sterac[0][0] = 2; // n from "STERACn" tag
+    oad->v3000->lists_sterac[0][1] = 1; // number of members in collection
+    oad->v3000->lists_sterac[0][2] = 1; // member atom numbers
+
+    // STERAC1 ATOMS=(2 2 3)
+    oad->v3000->lists_sterac[1][0] = 1; // STERAC1 ATOMS=(2 2 3)
+    oad->v3000->lists_sterac[1][1] = 2; // number of members in collection
+    oad->v3000->lists_sterac[1][2] = 2; // member atom numbers
+    oad->v3000->lists_sterac[1][3] = 3; // member atom numbers
+
+    oad->v3000->n_sterel = 2;
+    oad->v3000->lists_sterel = (int **)inchi_calloc(oad->v3000->n_sterel, sizeof(int*));
+    oad->v3000->lists_sterel[0] = (int *)inchi_calloc(2 + 2, sizeof(int));
+    oad->v3000->lists_sterel[1] = (int *)inchi_calloc(2 + 1, sizeof(int));
+
+    // STEREL1 ATOMS=(2 12 13)
+    oad->v3000->lists_sterel[0][0] = 1;  // n from "STERELn" tag
+    oad->v3000->lists_sterel[0][1] = 2;  // number of members in collection
+    oad->v3000->lists_sterel[0][2] = 12; // member atom numbers
+    oad->v3000->lists_sterel[0][3] = 13; // member atom numbers
+
+    // STEREL2 ATOMS=(1 14)
+    oad->v3000->lists_sterel[1][0] = 2;  // n from "STERELn" tag
+    oad->v3000->lists_sterel[1][1] = 1;  // number of members in collection
+    oad->v3000->lists_sterel[1][2] = 14; // member atom numbers
+
+    INCHI_SORT *inchi_sort = (INCHI_SORT*)inchi_calloc(1, sizeof(INCHI_SORT));
+
+    int num_at = 8;
+    int num_iso_at = 1;
+    int alloc_mode = 0;
+    int bOrigatomflag = 0;
+    int found_num_bonds = 0;
+    int found_num_isotopic = 0;
+
+    inp_ATOM *atoms = CreateInpAtom(num_at);
+    INChI *inchi = Alloc_INChI(atoms, num_at, &found_num_bonds, &found_num_isotopic, 0);
+    inchi->nNumberOfAtoms = num_at;
+
+    INChI_Aux *pAux = Alloc_INChI_Aux(num_at, num_iso_at, alloc_mode, bOrigatomflag);
+
+    pAux->nNumberOfAtoms = num_at;
+    // pAux->nOrigAtNosInCanonOrd = (AT_NUMB*)inchi_calloc(num_at, sizeof(AT_NUMB));
+
+    // canonical atom i+1 maps to original atom i+1
+    pAux->nOrigAtNosInCanonOrd[0] = 4;
+    pAux->nOrigAtNosInCanonOrd[1] = 5;
+    pAux->nOrigAtNosInCanonOrd[2] = 1;
+    pAux->nOrigAtNosInCanonOrd[3] = 2;
+    pAux->nOrigAtNosInCanonOrd[4] = 3;
+    pAux->nOrigAtNosInCanonOrd[5] = 12;
+    pAux->nOrigAtNosInCanonOrd[6] = 13;
+    pAux->nOrigAtNosInCanonOrd[7] = 14;
+
+    inchi_sort->pINChI[0] = inchi;
+    inchi_sort->pINChI_Aux[0] = pAux;
+    io.pINChISort = inchi_sort;
+
+    io.bOutType = OUT_TN;
+    io.num_components = 1;
+    io.sDifSegs[0][DIFS_s_STYPE] = DIFV_OUTPUT_FILL_T;
+    io.nCurINChISegment = 0;
+    io.iCurTautMode = 0;
+    io.bPlainTextTags = 1;
+    io.bRelativeStereo[0] = 0;
+    io.bRacemicStereo[0] = 0;
+    io.bAlways = 0;
+    io.nTag = 2; // plain text
+    io.bTag1 = IL_STER;
+    io.bTag2 = IL_STER | IL_TYPS;
+
+    inchi_strbuf_init(&strbuf, INCHI_STRBUF_INITIAL_SIZE, INCHI_STRBUF_SIZE_INCREMENT);
+    inchi_ios_init(&out_file, INCHI_IOS_TYPE_STRING, nullptr);
+
+    int ret = OutputINCHI_StereoLayer_EnhancedStereo(&cg, &out_file, &strbuf, &io, oad, (char*)"", (char*)"");
+
+    // EXPECT_EQ(std::string(strbuf.pStr), "/s1(4,5)2(12,13;14)3(1;2,3)");
+    EXPECT_EQ(std::string(strbuf.pStr), "/s1(1,2)2(6,7)(8)3(3)(4,5)");
+    EXPECT_EQ(ret, 0);
+
+    for (int i = 0; i < oad->v3000->n_steabs; i++) {
+        inchi_free(oad->v3000->lists_steabs[i]);
+    }
+    inchi_free(oad->v3000->lists_steabs);
+
+    for (int i = 0; i < oad->v3000->n_sterel; i++) {
+        inchi_free(oad->v3000->lists_sterel[i]);
+    }
+    inchi_free(oad->v3000->lists_sterel);
+
+    for (int i = 0; i < oad->v3000->n_sterac; i++) {
+        inchi_free(oad->v3000->lists_sterac[i]);
+    }
+    inchi_free(oad->v3000->lists_sterac);
+
+    inchi_free(oad->v3000);
+    inchi_free(oad);
+
+    inchi_free(inchi_sort);
+
+    FreeInpAtom(&atoms);
+    Free_INChI_Aux(&pAux);
+    Free_INChI(&inchi);
+
+    inchi_strbuf_close(&strbuf);
+    inchi_ios_close(&out_file);
+}
+
diff --git a/INCHI-1-TEST/tests/test_unit/test_ichiprt2.cpp b/INCHI-1-TEST/tests/test_unit/test_ichiprt2.cpp
new file mode 100644
index 00000000..fdb7f5ab
--- /dev/null
+++ b/INCHI-1-TEST/tests/test_unit/test_ichiprt2.cpp
@@ -0,0 +1,378 @@
+#include <gtest/gtest.h>
+#include <gmock/gmock.h>
+
+extern "C"
+{
+#include "../../../INCHI-1-SRC/INCHI_BASE/src/ichiprt2.c"
+#include "../../../INCHI-1-SRC/INCHI_BASE/src/ichi_io.h"
+}
+
+TEST(test_ichiprt2, MakeStereoString_outputs_expected_sp3_string)
+{
+    AT_NUMB at1[8] = {3,4,5,6,7,8,9,10};
+    S_CHAR parity[8] = {1,1,2,2,1,2,2,1};
+
+    INCHI_IOS_STRING strbuf = {0};
+
+    inchi_strbuf_init(&strbuf, INCHI_STRBUF_INITIAL_SIZE, INCHI_STRBUF_SIZE_INCREMENT);
+
+    int bOverflow = 0;
+    int ret = MakeStereoString(at1, nullptr, parity, 0, 8, &strbuf, 0, &bOverflow);
+
+    EXPECT_EQ(strbuf.nUsedLength, strlen(strbuf.pStr));
+    EXPECT_NE(std::string(strbuf.pStr).find("3-,4-,5+,6+,7-,8+,9+,10-"), std::string::npos);
+    EXPECT_EQ(std::string(strbuf.pStr), "3-,4-,5+,6+,7-,8+,9+,10-");
+    EXPECT_EQ(strbuf.pStr[0], '3');
+    EXPECT_EQ(bOverflow, 0);
+    EXPECT_EQ(ret, 24);
+
+    inchi_strbuf_close(&strbuf);
+}
+
+TEST(test_ichiprt2, MakeMult_mult_gt_1_appends_number_and_delim)
+{
+    INCHI_IOS_STRING strbuf = {0};
+    inchi_strbuf_init(&strbuf, INCHI_STRBUF_INITIAL_SIZE, INCHI_STRBUF_SIZE_INCREMENT);
+
+    int bOverflow = 0;
+    int ret = MakeMult(5, "-", &strbuf, 0, &bOverflow);
+
+    EXPECT_EQ(std::string(strbuf.pStr), "5-");
+    EXPECT_EQ(ret, 2);
+    EXPECT_EQ(bOverflow, 0);
+
+    inchi_strbuf_close(&strbuf);
+}
+
+TEST(test_ichiprt2, MakeMult_mult_2)
+{
+    INCHI_IOS_STRING strbuf = {0};
+    inchi_strbuf_init(&strbuf, INCHI_STRBUF_INITIAL_SIZE, INCHI_STRBUF_SIZE_INCREMENT);
+
+    int bOverflow = 0;
+    int ret = MakeMult(10, "+", &strbuf, 0, &bOverflow);
+
+    EXPECT_EQ(std::string(strbuf.pStr), "10+");
+    EXPECT_EQ(ret, 3);
+    EXPECT_EQ(bOverflow, 0);
+
+    inchi_strbuf_close(&strbuf);
+}
+
+TEST(test_ichiprt2, MakeMult_mult_eq_1_does_nothing)
+{
+    INCHI_IOS_STRING strbuf = {0};
+    inchi_strbuf_init(&strbuf, INCHI_STRBUF_INITIAL_SIZE, INCHI_STRBUF_SIZE_INCREMENT);
+    inchi_strbuf_printf(&strbuf, "start");
+
+    int bOverflow = 0;
+    int ret = MakeMult(1, "-", &strbuf, 0, &bOverflow);
+
+    EXPECT_EQ(std::string(strbuf.pStr), "start");
+    EXPECT_EQ(ret, 0);
+    EXPECT_EQ(bOverflow, 0);
+
+    inchi_strbuf_close(&strbuf);
+}
+
+TEST(test_ichiprt2, Eql_INChI_Stereo_sp2_equal)
+{
+    // Setup two identical SP2 stereo objects
+    INChI_Stereo s1 = {0}, s2 = {0};
+    int num_bonds = 2;
+    AT_NUMB bond_atom1[2] = {1, 3};
+    AT_NUMB bond_atom2[2] = {2, 4};
+    S_CHAR b_parity[2] = {1, 2};
+
+    s1.nNumberOfStereoBonds = num_bonds;
+    s1.nBondAtom1 = bond_atom1;
+    s1.nBondAtom2 = bond_atom2;
+    s1.b_parity = b_parity;
+
+    s2.nNumberOfStereoBonds = num_bonds;
+    s2.nBondAtom1 = bond_atom1;
+    s2.nBondAtom2 = bond_atom2;
+    s2.b_parity = b_parity;
+
+    // Should be equal
+    EXPECT_EQ(Eql_INChI_Stereo(&s1, EQL_SP2, &s2, EQL_SP2, 0), 1);
+}
+
+TEST(test_ichiprt2, Eql_INChI_Stereo_sp2_not_equal)
+{
+    // Setup two different SP2 stereo objects
+    INChI_Stereo s1 = {0}, s2 = {0};
+    AT_NUMB bond_atom1_1[2] = {1, 3};
+    AT_NUMB bond_atom2_1[2] = {2, 4};
+    S_CHAR b_parity_1[2] = {1, 2};
+
+    AT_NUMB bond_atom1_2[2] = {1, 5};
+    AT_NUMB bond_atom2_2[2] = {2, 6};
+    S_CHAR b_parity_2[2] = {1, 1};
+
+    s1.nNumberOfStereoBonds = 2;
+    s1.nBondAtom1 = bond_atom1_1;
+    s1.nBondAtom2 = bond_atom2_1;
+    s1.b_parity = b_parity_1;
+
+    s2.nNumberOfStereoBonds = 2;
+    s2.nBondAtom1 = bond_atom1_2;
+    s2.nBondAtom2 = bond_atom2_2;
+    s2.b_parity = b_parity_2;
+
+    // Should not be equal
+    EXPECT_EQ(Eql_INChI_Stereo(&s1, EQL_SP2, &s2, EQL_SP2, 0), 0);
+}
+
+TEST(test_ichiprt2, Eql_INChI_Stereo_sp2_exists)
+{
+    // s1 has stereo, s2 is nullptr, eql2 is EQL_EXISTS
+    INChI_Stereo s1 = {0};
+    AT_NUMB bond_atom1[1] = {1};
+    AT_NUMB bond_atom2[1] = {2};
+    S_CHAR b_parity[1] = {1};
+
+    s1.nNumberOfStereoBonds = 1;
+    s1.nBondAtom1 = bond_atom1;
+    s1.nBondAtom2 = bond_atom2;
+    s1.b_parity = b_parity;
+
+    EXPECT_EQ(Eql_INChI_Stereo(&s1, EQL_SP2, nullptr, EQL_EXISTS, 0), 1);
+}
+
+TEST(test_ichiprt2, Eql_INChI_Stereo_sp3_equal)
+{
+    // Setup two identical SP3 stereo objects
+    INChI_Stereo s1 = {0}, s2 = {0};
+    int num_centers = 2;
+    AT_NUMB nNumber1[2] = {5, 6};
+    S_CHAR t_parity1[2] = {1, 2};
+
+    s1.nNumberOfStereoCenters = num_centers;
+    s1.nNumber = nNumber1;
+    s1.t_parity = t_parity1;
+
+    s2.nNumberOfStereoCenters = num_centers;
+    s2.nNumber = nNumber1;
+    s2.t_parity = t_parity1;
+
+    // Should be equal
+    EXPECT_EQ(Eql_INChI_Stereo(&s1, EQL_SP3, &s2, EQL_SP3, 0), 1);
+}
+
+TEST(test_ichiprt2, Eql_INChI_Stereo_sp3_not_equal)
+{
+    // Setup two different SP3 stereo objects
+    INChI_Stereo s1 = {0}, s2 = {0};
+    int num_centers = 2;
+    AT_NUMB nNumber1[2] = {5, 6};
+    S_CHAR t_parity1[2] = {1, 2};
+
+    AT_NUMB nNumber2[2] = {7, 8};
+    S_CHAR t_parity2[2] = {2, 1};
+
+    s1.nNumberOfStereoCenters = num_centers;
+    s1.nNumber = nNumber1;
+    s1.t_parity = t_parity1;
+
+    s2.nNumberOfStereoCenters = num_centers;
+    s2.nNumber = nNumber2;
+    s2.t_parity = t_parity2;
+
+    // Should not be equal
+    EXPECT_EQ(Eql_INChI_Stereo(&s1, EQL_SP3, &s2, EQL_SP3, 0), 0);
+}
+
+TEST(test_ichiprt2, test_compare_ints_basic)
+{
+    int a = 5, b = 10, c = 5;
+
+    // a < b
+    EXPECT_LT(compare_ints(&a, &b), 0);
+
+    // b > a
+    EXPECT_GT(compare_ints(&b, &a), 0);
+
+    // a == c
+    EXPECT_EQ(compare_ints(&a, &c), 0);
+}
+
+TEST(test_ichiprt2, MakeNumber_EnhStereo_decimal)
+{
+    INCHI_IOS_STRING strbuf = {0};
+    inchi_strbuf_init(&strbuf, INCHI_STRBUF_INITIAL_SIZE, INCHI_STRBUF_SIZE_INCREMENT);
+
+    int bOverflow = 0;
+    int nCtMode = 0; // decimal mode
+
+    int n = MakeNumber_EnhStereo(42, ",", &strbuf, nCtMode, &bOverflow);
+
+    EXPECT_EQ(bOverflow, 0);
+    EXPECT_EQ(std::string(strbuf.pStr), "42,");
+    EXPECT_EQ(n, 3);
+
+    inchi_strbuf_close(&strbuf);
+}
+
+TEST(test_ichiprt2, MakeNumber_EnhStereo_abc)
+{
+    INCHI_IOS_STRING strbuf = {0};
+    inchi_strbuf_init(&strbuf, INCHI_STRBUF_INITIAL_SIZE, INCHI_STRBUF_SIZE_INCREMENT);
+    int bOverflow = 0;
+    int nCtMode = CT_MODE_ABC_NUMBERS; // alphabetic mode
+
+    int n = MakeNumber_EnhStereo(28, ";", &strbuf, nCtMode, &bOverflow);
+
+    EXPECT_EQ(bOverflow, 0);
+    // 28 in base-27 is "aa", so expect "Aa;"
+    EXPECT_EQ(std::string(strbuf.pStr), "Aa;");
+    EXPECT_EQ(n, 3);
+
+    inchi_strbuf_close(&strbuf);
+}
+
+TEST(test_ichiprt2, MakeEnhStereoString_basic)
+{
+    // Setup INChI_Aux with 3 atoms, canonical numbers 1, 2, 3
+    INChI_Aux aux = {0};
+    AT_NUMB orig_atoms[] = {1, 2, 3};
+    aux.nNumberOfAtoms = 3;
+    aux.nOrigAtNosInCanonOrd = orig_atoms;
+
+    // Enhanced stereo group: one group, 3 atoms (original numbers 1,2,3)
+    int group1[] = {0, 3, 1, 2, 3}; // [unused, n_atoms, orig_atom1, orig_atom2, orig_atom3]
+    int* enh_stereo[1] = {group1};
+
+    INCHI_IOS_STRING strbuf = {0};
+    inchi_strbuf_init(&strbuf, INCHI_STRBUF_INITIAL_SIZE, INCHI_STRBUF_SIZE_INCREMENT);
+    int bOverflow = 0;
+    int nCtMode = 0;
+
+    int len = MakeEnhStereoString(&aux, &strbuf, "1", enh_stereo, 1, nCtMode, &bOverflow);
+
+    EXPECT_EQ(bOverflow, 0);
+    EXPECT_EQ(std::string(strbuf.pStr), "1(1,2,3)");
+    EXPECT_EQ(len, 8);
+
+    inchi_strbuf_close(&strbuf);
+}
+
+TEST(test_ichiprt2, MakeEnhStereoString_multiple_groups)
+{
+    INChI_Aux aux = {0};
+    AT_NUMB orig_atoms[] = {1, 2, 3, 4};
+    aux.nNumberOfAtoms = 4;
+    aux.nOrigAtNosInCanonOrd = orig_atoms;
+
+    int group1[] = {0, 2, 1, 2}; // [unused, n_atoms, orig_atom1, orig_atom2]
+    int group2[] = {0, 2, 3, 4}; // [unused, n_atoms, orig_atom3, orig_atom4]
+    int* enh_stereo[2] = {group1, group2};
+
+    INCHI_IOS_STRING strbuf = {0};
+    inchi_strbuf_init(&strbuf, INCHI_STRBUF_INITIAL_SIZE, INCHI_STRBUF_SIZE_INCREMENT);
+    int bOverflow = 0;
+    int nCtMode = 0;
+
+    int len = MakeEnhStereoString(&aux, &strbuf, "2", enh_stereo, 2, nCtMode, &bOverflow);
+
+    EXPECT_EQ(bOverflow, 0);
+    EXPECT_EQ(std::string(strbuf.pStr), "2(1,2)(3,4)");
+    EXPECT_EQ(len, 11);
+
+    inchi_strbuf_close(&strbuf);
+}
+
+TEST(test_ichiprt2, MakeEnhStereoString_empty_group)
+{
+    INChI_Aux aux = {0};
+    AT_NUMB orig_atoms[] = {1, 2, 3};
+    aux.nNumberOfAtoms = 3;
+    aux.nOrigAtNosInCanonOrd = orig_atoms;
+
+    // Group with no valid atoms
+    int group1[] = {0, 2, 99, 100}; // [unused, n_atoms, orig_atom99, orig_atom100]
+    int* enh_stereo[1] = {group1};
+
+    INCHI_IOS_STRING strbuf = {0};
+    inchi_strbuf_init(&strbuf, INCHI_STRBUF_INITIAL_SIZE, INCHI_STRBUF_SIZE_INCREMENT);
+    int bOverflow = 0;
+    int nCtMode = 0;
+
+    int len = MakeEnhStereoString(&aux, &strbuf, "3", enh_stereo, 1, nCtMode, &bOverflow);
+
+    EXPECT_EQ(bOverflow, 0);
+    EXPECT_EQ(std::string(strbuf.pStr), "");
+    EXPECT_EQ(len, 0);
+
+    inchi_strbuf_close(&strbuf);
+}
+
+TEST(test_ichiprt2, MakeSlayerString_basic)
+{
+
+    ORIG_ATOM_DATA *oad = (ORIG_ATOM_DATA *)inchi_calloc(1, sizeof(ORIG_ATOM_DATA));
+
+    OAD_V3000 *v3000 = (OAD_V3000 *)inchi_calloc(1, sizeof(OAD_V3000));
+
+    // One absolute group: 2 atoms (original numbers 1,2)
+    int group_abs[] = {0, 2, 1, 2};
+    v3000->n_steabs = 1;
+    v3000->lists_steabs = (int**)inchi_calloc(1, sizeof(int*));
+    v3000->lists_steabs[0] = group_abs;
+
+    // One relative group: 1 atom (original number 3)
+    int group_rel[] = {0, 1, 3};
+    v3000->n_sterel = 1;
+    v3000->lists_sterel = (int**)inchi_calloc(1, sizeof(int*));
+    v3000->lists_sterel[0] = group_rel;
+
+    // No racemic groups
+    v3000->n_sterac = 0;
+
+    oad->v3000 = v3000;
+
+    // Setup INCHI_SORT and INChI_Aux
+    INCHI_SORT *inchi_sort = (INCHI_SORT*)inchi_calloc(1, sizeof(INCHI_SORT));
+
+    int num_at = 8;
+    int num_iso_at = 1;
+    int alloc_mode = 0;
+    int bOrigatomflag = 0;
+    int found_num_bonds = 0;
+    int found_num_isotopic = 0;
+
+    inp_ATOM *atoms = CreateInpAtom(num_at);
+    INChI *inchi = Alloc_INChI(atoms, num_at, &found_num_bonds, &found_num_isotopic, 0);
+    inchi->nNumberOfAtoms = num_at;
+
+    INChI_Aux *pAux = Alloc_INChI_Aux(num_at, num_iso_at, alloc_mode, bOrigatomflag);
+    pAux->nNumberOfAtoms = 3;
+    pAux->nOrigAtNosInCanonOrd[0] = 1;
+    pAux->nOrigAtNosInCanonOrd[1] = 2;
+    pAux->nOrigAtNosInCanonOrd[2] = 3;
+
+    inchi_sort->pINChI_Aux[0] = pAux;
+    inchi_sort->pINChI[0] = inchi;
+
+    INCHI_IOS_STRING strbuf = {0};
+    inchi_strbuf_init(&strbuf, INCHI_STRBUF_INITIAL_SIZE, INCHI_STRBUF_SIZE_INCREMENT);
+    int bOverflow = 0;
+    int nCtMode = 0;
+
+    int len = MakeSlayerString(oad, inchi_sort, &strbuf, OUT_TN, 1, nCtMode, &bOverflow);
+
+    EXPECT_EQ(bOverflow, 0);
+    EXPECT_EQ(std::string(strbuf.pStr), "1(1,2)2(3)");
+    EXPECT_EQ(len, 10);
+
+    inchi_free(oad->v3000->lists_steabs);
+    inchi_free(oad->v3000->lists_sterel);
+    inchi_free(oad->v3000);
+    inchi_free(oad);
+    inchi_free(inchi_sort);
+
+    inchi_strbuf_close(&strbuf);
+    FreeInpAtom(&atoms);
+    Free_INChI_Aux(&pAux);
+    Free_INChI(&inchi);
+}
diff --git a/INCHI-1-TEST/tests/test_unit/test_ichiprt3.cpp b/INCHI-1-TEST/tests/test_unit/test_ichiprt3.cpp
new file mode 100644
index 00000000..c5b8def9
--- /dev/null
+++ b/INCHI-1-TEST/tests/test_unit/test_ichiprt3.cpp
@@ -0,0 +1,260 @@
+#include <gtest/gtest.h>
+#include <gmock/gmock.h>
+
+extern "C"
+{
+#include "../../../INCHI-1-SRC/INCHI_BASE/src/ichiprt3.c"
+#include "../../../INCHI-1-SRC/INCHI_BASE/src/strutil.c"
+#include "../../../INCHI-1-SRC/INCHI_BASE/src/ichi_io.h"
+#include "../../../INCHI-1-SRC/INCHI_BASE/src/ichimake.h"
+}
+
+TEST(test_ichiprt3, test_str_Sp2_outputs_expected_sp2_string_1)
+{
+    int num_at = 2;
+    int num_bonds = 1;
+    int bond_atom1[1] = {4};
+    int bond_atom2[1] = {3};
+    S_CHAR b_parity[1] = {1}; // 1 = -, 2 = +
+
+    INChI_Stereo* stereo = Alloc_INChI_Stereo(num_at, num_bonds);
+    stereo->nNumberOfStereoBonds = num_bonds;
+    for (int i = 0; i < num_bonds; i++) {
+        stereo->nBondAtom1[i] = bond_atom1[i];
+        stereo->nBondAtom2[i] = bond_atom2[i];
+        stereo->b_parity[i] = b_parity[i];
+    }
+
+    INChI inchi = {0};
+    inchi.nNumberOfAtoms = num_at;
+    inchi.Stereo = stereo;
+
+    INCHI_SORT inchi_sort = {0};
+    inchi_sort.pINChI[0] = &inchi;
+
+    INCHI_IOS_STRING strbuf = {0};
+    inchi_strbuf_init(&strbuf, INCHI_STRBUF_INITIAL_SIZE, INCHI_STRBUF_SIZE_INCREMENT);
+
+    int bOverflow = 0;
+    int bOutputType = OUT_N1; // OUT_TN
+    int taut_mode = 0; // CT_MODE_ABC_NUMBERS
+    int num_components = 1;
+
+    int bSecondNonTautPass = 0;
+    int bOmitRepetitions = 0;
+    int bUseMulipliers = 1;
+
+    int ret = str_Sp2(
+        &inchi_sort,
+        NULL,
+        &strbuf,
+        &bOverflow,
+        bOutputType,
+        taut_mode,
+        num_components,
+        bSecondNonTautPass,
+        bOmitRepetitions,
+        bUseMulipliers
+    );
+
+    EXPECT_EQ(strbuf.nUsedLength, strlen(strbuf.pStr));
+    EXPECT_EQ(std::string(strbuf.pStr), "4-3-");
+    EXPECT_EQ(strbuf.pStr[0], '4');
+    EXPECT_EQ(bOverflow, 0);
+
+    // The return value should be the length of the output string
+    EXPECT_EQ(ret, 4);
+
+    inchi_strbuf_close(&strbuf);
+    Free_INChI_Stereo(stereo);
+    inchi_free(stereo);
+}
+
+TEST(test_ichiprt3, test_str_Sp2_outputs_expected_sp2_string_2)
+{
+    int num_at = 4;
+    int num_bonds = 2;
+    int bond_atom1[2] = {1, 3};
+    int bond_atom2[2] = {2, 4};
+    S_CHAR b_parity[2] = {1, 2}; // 1 = -, 2 = +
+
+    INChI_Stereo* stereo = Alloc_INChI_Stereo(num_at, num_bonds);
+    stereo->nNumberOfStereoBonds = num_bonds;
+    for (int i = 0; i < num_bonds; i++) {
+        stereo->nBondAtom1[i] = bond_atom1[i];
+        stereo->nBondAtom2[i] = bond_atom2[i];
+        stereo->b_parity[i] = b_parity[i];
+    }
+
+    INChI inchi = {0};
+    inchi.nNumberOfAtoms = num_at;
+    inchi.Stereo = stereo;
+
+    INCHI_SORT inchi_sort = {0};
+    inchi_sort.pINChI[0] = &inchi;
+
+    INCHI_IOS_STRING strbuf = {0};
+    inchi_strbuf_init(&strbuf, INCHI_STRBUF_INITIAL_SIZE, INCHI_STRBUF_SIZE_INCREMENT);
+
+    int bOverflow = 0;
+    int bOutputType = OUT_N1; // OUT_TN
+    int taut_mode = 0; // CT_MODE_ABC_NUMBERS
+    int num_components = 1;
+
+    int bSecondNonTautPass = 0;
+    int bOmitRepetitions = 0;
+    int bUseMulipliers = 1;
+
+    int ret = str_Sp2(
+        &inchi_sort,
+        NULL,
+        &strbuf,
+        &bOverflow,
+        bOutputType,
+        taut_mode,
+        num_components,
+        bSecondNonTautPass,
+        bOmitRepetitions,
+        bUseMulipliers
+    );
+
+    EXPECT_EQ(strbuf.nUsedLength, strlen(strbuf.pStr));
+    EXPECT_EQ(std::string(strbuf.pStr), "1-2-,3-4+");
+    EXPECT_EQ(strbuf.pStr[0], '1');
+    EXPECT_EQ(bOverflow, 0);
+
+    // The return value should be the length of the output string
+    EXPECT_EQ(ret, 9);
+
+    inchi_strbuf_close(&strbuf);
+    Free_INChI_Stereo(stereo);
+    inchi_free(stereo);
+}
+
+TEST(test_ichiprt3, test_str_Sp3_outputs_expected_sp3_string)
+{
+    int numbers[8] = {3,4,5,6,7,8,9,10};
+    S_CHAR parities[8] = {1,1,2,2,1,2,2,1}; // 1 = -, 2 = +
+    int num_at = 8;
+    static INChI_Stereo *stereo = Alloc_INChI_Stereo( num_at, 0 );
+    stereo->nNumberOfStereoCenters = num_at;
+
+    for (int i = 0; i < num_at; i++) {
+        stereo->nNumber[i] = numbers[i];
+        stereo->t_parity[i] = parities[i];
+    }
+
+    INChI inchi = {0};
+    inchi.nNumberOfAtoms = 10;
+    inchi.Stereo = stereo;
+
+    INCHI_SORT inchi_sort = {0};
+    inchi_sort.pINChI[0] = &inchi;
+
+    INCHI_IOS_STRING strbuf = {0};
+    inchi_strbuf_init(&strbuf, INCHI_STRBUF_INITIAL_SIZE, INCHI_STRBUF_SIZE_INCREMENT);
+
+
+    int bOverflow = 0;
+    int num_components = 1;
+
+    int bIsotopicRelativeStereo = 0; // INCHI_FLAG_REL_STEREO
+    int bIsotopicRacemicStereo = 0; // INCHI_FLAG_RAC_STEREO
+
+    int bRelRac = bIsotopicRelativeStereo || bIsotopicRacemicStereo;
+
+    int ret = str_Sp3(&inchi_sort, NULL, &strbuf, &bOverflow, 0, 0, num_components, bRelRac, 0, 0, 0);
+
+    EXPECT_EQ(strbuf.nUsedLength, strlen(strbuf.pStr));
+    EXPECT_EQ(std::string(strbuf.pStr), "3-,4-,5+,6+,7-,8+,9+,10-");
+    EXPECT_EQ(strbuf.pStr[0], '3');
+    EXPECT_EQ(bOverflow, 0);
+
+    EXPECT_EQ(ret, 24);
+
+    inchi_strbuf_close(&strbuf);
+
+    Free_INChI_Stereo(stereo);
+}
+
+TEST(test_ichiprt3, test_str_StereoAbsInv_1)
+{
+
+    int num_at = 2;
+    int num_bonds = 1;
+    int found_num_bonds = 0;
+    int found_num_isotopic = 0;
+    inp_ATOM *at = CreateInpAtom(num_at);
+    INChI *inchi = Alloc_INChI(at, num_at, &found_num_bonds, &found_num_isotopic, 0);
+    inchi->Stereo->nCompInv2Abs = -1;
+    inchi->nNumberOfAtoms = num_at;
+
+    INCHI_SORT *inchi_sort = (INCHI_SORT*)calloc(1, sizeof(INCHI_SORT));
+    inchi_sort->pINChI[TAUT_YES] = inchi;
+
+    INCHI_IOS_STRING strbuf = {0};
+    inchi_strbuf_init(&strbuf, INCHI_STRBUF_INITIAL_SIZE, INCHI_STRBUF_SIZE_INCREMENT);
+
+    int bOverflow = 0;
+    int bOutType = OUT_TN;
+    int num_components = 1;
+
+    // int test_ret0 = HAS_T(inchi_sort);
+    // int test_ret1 = GET_II( bOutType, inchi_sort);
+
+    int ret = str_StereoAbsInv(inchi_sort, &strbuf, &bOverflow, bOutType, num_components);
+
+    EXPECT_EQ(ret, 1);
+    EXPECT_EQ(std::string(strbuf.pStr), "1");
+    EXPECT_EQ(bOverflow, 0);
+
+    inchi_strbuf_close(&strbuf);
+
+    Free_INChI(&inchi);
+
+    FreeInpAtom(&at);
+
+    free(inchi_sort);
+}
+
+TEST(test_ichiprt3, test_str_StereoAbsInv_2)
+{
+
+    int num_at = 2;
+    int num_bonds = 1;
+    int found_num_bonds = 0;
+    int found_num_isotopic = 0;
+    inp_ATOM *at = CreateInpAtom(num_at);
+    static INChI *inchi = Alloc_INChI(at, num_at, &found_num_bonds, &found_num_isotopic, 0);
+
+    inchi->Stereo->nCompInv2Abs = 1;
+
+    inchi->nNumberOfAtoms = num_at;
+
+    INCHI_SORT *inchi_sort = (INCHI_SORT*)calloc(1, sizeof(INCHI_SORT));
+    inchi_sort->pINChI[TAUT_YES] = inchi;
+
+    INCHI_IOS_STRING strbuf = {0};
+    inchi_strbuf_init(&strbuf, INCHI_STRBUF_INITIAL_SIZE, INCHI_STRBUF_SIZE_INCREMENT);
+
+    int bOverflow = 0;
+    int bOutType = OUT_TN;
+    int num_components = 1;
+
+    // int test_ret0 = HAS_T(inchi_sort);
+    // int test_ret1 = GET_II( bOutType, inchi_sort);
+
+    int ret = str_StereoAbsInv(inchi_sort, &strbuf, &bOverflow, bOutType, num_components);
+
+    EXPECT_EQ(ret, 1);
+    EXPECT_EQ(std::string(strbuf.pStr), "0");
+    EXPECT_EQ(bOverflow, 0);
+
+    inchi_strbuf_close(&strbuf);
+
+    Free_INChI(&inchi);
+
+    FreeInpAtom(&at);
+
+    free(inchi_sort);
+}
diff --git a/INCHI-1-TEST/tests/test_unit/test_inpdef.cpp b/INCHI-1-TEST/tests/test_unit/test_inpdef.cpp
index 986b6c6d..d3a0228b 100644
--- a/INCHI-1-TEST/tests/test_unit/test_inpdef.cpp
+++ b/INCHI-1-TEST/tests/test_unit/test_inpdef.cpp
@@ -71,23 +71,6 @@ TEST(test_inpdef, test_CreateOrigInpDataFromMolfile_v3000_sgroup)
     inchi_ios_init(&input_stream, INCHI_IOS_TYPE_STRING, nullptr);
     inchi_ios_print_nodisplay(&input_stream, molblock);
 
-    // int ret = CreateOrigInpDataFromMolfile(
-    //     INCHI_IOSTREAM *inp_file,
-    //     ORIG_ATOM_DATA *orig_at_data,
-    //     int bMergeAllInputStructures,
-    //     int bGetOrigCoord,
-    //     int bDoNotAddH,
-    //     int treat_polymers,
-    //     int treat_NPZz,
-    //     const char *pSdfLabel,
-    //     char *pSdfValue,
-    //     unsigned long *lSdfId,
-    //     long *lMolfileNumber,
-    //     INCHI_MODE *pInpAtomFlags,
-    //     int *err,
-    //     char *pStrErr,
-    //     int bNoWarnings);
-
     ORIG_ATOM_DATA orig_at_data = {};
     int bMergeAllInputStructures = 0;
     int bGetOrigCoord = 0;
diff --git a/INCHI-1-TEST/tests/test_unit/test_mol_fmt.cpp b/INCHI-1-TEST/tests/test_unit/test_mol_fmt.cpp
index 23003716..cdf361e6 100644
--- a/INCHI-1-TEST/tests/test_unit/test_mol_fmt.cpp
+++ b/INCHI-1-TEST/tests/test_unit/test_mol_fmt.cpp
@@ -28,8 +28,6 @@ TEST(test_mol_fmt, test_MolfileStrnread)
 
 TEST(test_mol_fmt, test_MolfileReadField)
 {
-    // int MolfileReadField(void *data, int field_len, int data_type,  char **line_ptr)
-
     // SEG FAULT?
     // EXPECT_EQ(MolfileReadField(NULL, 0, MOL_FMT_STRING_DATA, NULL), 0); // no data, no line pointer
 
@@ -110,11 +108,6 @@ TEST(test_mol_fmt, test_MolfileReadField)
 
 TEST(test_mol_fmt, test_MolfileV3000ReadField)
 {
-
-    // int MolfileV3000ReadField(void *data,
-    //                           int data_type,
-    //                           char **line_ptr);
-
     int n_coll = 0;
 
     char source_data[] = "2 ATOMS=(1 1)";
@@ -362,31 +355,19 @@ TEST(test_mol_fmt, test_MolfileHasNoChemStruc)
 
 TEST(test_mol_fmt, test_FreeMolfileData)
 {
+    MOL_FMT_DATA *mfdata = (MOL_FMT_DATA *)calloc(1, sizeof(MOL_FMT_DATA));
 
-    MOL_FMT_DATA *mfdata;
+    MOL_FMT_HEADER_BLOCK *hdr = (MOL_FMT_HEADER_BLOCK *)calloc(1, sizeof(MOL_FMT_HEADER_BLOCK));
 
-    MOL_FMT_HEADER_BLOCK *hdr;
+    MOL_FMT_CTAB *ctab = (MOL_FMT_CTAB *)calloc(1, sizeof(MOL_FMT_CTAB));
+    MOL_FMT_ATOM *atoms = (MOL_FMT_ATOM *)calloc(1, sizeof(MOL_FMT_ATOM));
+    MOL_FMT_BOND *bonds = (MOL_FMT_BOND *)calloc(1, sizeof(MOL_FMT_BOND));
 
-    MOL_FMT_CTAB *ctab;
-    MOL_FMT_BOND *bonds;
-    MOL_FMT_ATOM *atoms;
+    MOL_FMT_SGROUPS *sgroups = (MOL_FMT_SGROUPS *)calloc(1, sizeof(MOL_FMT_SGROUPS));
 
-    MOL_FMT_SGROUPS *sgroups;
-    MOL_COORD *coords;
-    MOL_FMT_v3000 *v3000;
+    MOL_COORD *coords = (MOL_COORD *)calloc(1, sizeof(MOL_COORD));
 
-    mfdata = (MOL_FMT_DATA *)calloc(1, sizeof(MOL_FMT_DATA));
-
-    hdr = (MOL_FMT_HEADER_BLOCK *)calloc(1, sizeof(MOL_FMT_HEADER_BLOCK));
-
-    ctab = (MOL_FMT_CTAB *)calloc(1, sizeof(MOL_FMT_CTAB));
-    atoms = (MOL_FMT_ATOM *)calloc(1, sizeof(MOL_FMT_ATOM));
-    bonds = (MOL_FMT_BOND *)calloc(1, sizeof(MOL_FMT_BOND));
-
-    sgroups = (MOL_FMT_SGROUPS *)calloc(1, sizeof(MOL_FMT_SGROUPS));
-
-    coords = (MOL_COORD *)calloc(1, sizeof(MOL_COORD));
-    v3000 = (MOL_FMT_v3000 *)calloc(1, sizeof(MOL_FMT_v3000));
+    MOL_FMT_v3000 *v3000 = (MOL_FMT_v3000 *)calloc(1, sizeof(MOL_FMT_v3000));
 
     mfdata->hdr = *hdr;
 
@@ -472,21 +453,6 @@ TEST(test_mol_fmt, test_ReadMolfile_v2000)
     inchi_ios_init(&input_stream, INCHI_IOS_TYPE_STRING, nullptr);
     inchi_ios_print_nodisplay(&input_stream, molblock);
 
-    // MOL_FMT_DATA *ReadMolfile(INCHI_IOSTREAM *inp_file,
-    //                         MOL_FMT_HEADER_BLOCK *OnlyHeaderBlock,
-    //                         MOL_FMT_CTAB *OnlyCTab,
-    //                         int bGetOrigCoord,
-    //                         int treat_polymers,
-    //                         int treat_NPZz,
-    //                         char *pname,
-    //                         int lname,
-    //                         unsigned long *Id,
-    //                         const char *pSdfLabel,
-    //                         char *pSdfValue,
-    //                         int *err,
-    //                         char *pStrErr,
-    //                         int bNoWarnings)
-
     INCHI_IOSTREAM *inp_file = &input_stream;
     MOL_FMT_HEADER_BLOCK *OnlyHeaderBlock = nullptr;
     MOL_FMT_CTAB *OnlyCTab = nullptr;
@@ -599,21 +565,6 @@ TEST(test_mol_fmt, test_ReadMolfile_v3000)
     inchi_ios_init(&input_stream, INCHI_IOS_TYPE_STRING, nullptr);
     inchi_ios_print_nodisplay(&input_stream, molblock);
 
-    // MOL_FMT_DATA *ReadMolfile(INCHI_IOSTREAM *inp_file,
-    //                         MOL_FMT_HEADER_BLOCK *OnlyHeaderBlock,
-    //                         MOL_FMT_CTAB *OnlyCTab,
-    //                         int bGetOrigCoord,
-    //                         int treat_polymers,
-    //                         int treat_NPZz,
-    //                         char *pname,
-    //                         int lname,
-    //                         unsigned long *Id,
-    //                         const char *pSdfLabel,
-    //                         char *pSdfValue,
-    //                         int *err,
-    //                         char *pStrErr,
-    //                         int bNoWarnings)
-
     INCHI_IOSTREAM *inp_file = &input_stream;
     MOL_FMT_HEADER_BLOCK *OnlyHeaderBlock = nullptr;
     MOL_FMT_CTAB *OnlyCTab = nullptr;
@@ -696,21 +647,6 @@ TEST(test_mol_fmt, test_ReadMolfile_v3000_collection_1)
     inchi_ios_init(&input_stream, INCHI_IOS_TYPE_STRING, nullptr);
     inchi_ios_print_nodisplay(&input_stream, molblock);
 
-    // MOL_FMT_DATA *ReadMolfile(INCHI_IOSTREAM *inp_file,
-    //                         MOL_FMT_HEADER_BLOCK *OnlyHeaderBlock,
-    //                         MOL_FMT_CTAB *OnlyCTab,
-    //                         int bGetOrigCoord,
-    //                         int treat_polymers,
-    //                         int treat_NPZz,
-    //                         char *pname,
-    //                         int lname,
-    //                         unsigned long *Id,
-    //                         const char *pSdfLabel,
-    //                         char *pSdfValue,
-    //                         int *err,
-    //                         char *pStrErr,
-    //                         int bNoWarnings)
-
     INCHI_IOSTREAM *inp_file = &input_stream;
     MOL_FMT_HEADER_BLOCK *OnlyHeaderBlock = nullptr;
     MOL_FMT_CTAB *OnlyCTab = nullptr;
@@ -829,21 +765,6 @@ TEST(test_mol_fmt, test_ReadMolfile_v3000_collection_2)
     inchi_ios_init(&input_stream, INCHI_IOS_TYPE_STRING, nullptr);
     inchi_ios_print_nodisplay(&input_stream, molblock);
 
-    // MOL_FMT_DATA *ReadMolfile(INCHI_IOSTREAM *inp_file,
-    //                         MOL_FMT_HEADER_BLOCK *OnlyHeaderBlock,
-    //                         MOL_FMT_CTAB *OnlyCTab,
-    //                         int bGetOrigCoord,
-    //                         int treat_polymers,
-    //                         int treat_NPZz,
-    //                         char *pname,
-    //                         int lname,
-    //                         unsigned long *Id,
-    //                         const char *pSdfLabel,
-    //                         char *pSdfValue,
-    //                         int *err,
-    //                         char *pStrErr,
-    //                         int bNoWarnings)
-
     INCHI_IOSTREAM *inp_file = &input_stream;
     MOL_FMT_HEADER_BLOCK *OnlyHeaderBlock = nullptr;
     MOL_FMT_CTAB *OnlyCTab = nullptr;
diff --git a/INCHI-1-TEST/tests/test_unit/test_strutil.cpp b/INCHI-1-TEST/tests/test_unit/test_strutil.cpp
index f09afffe..3654e48d 100644
--- a/INCHI-1-TEST/tests/test_unit/test_strutil.cpp
+++ b/INCHI-1-TEST/tests/test_unit/test_strutil.cpp
@@ -13,7 +13,6 @@ TEST(test_strutil, test_ExtractConnectedComponent)
     inp_ATOM *new_mol = CreateInpAtom(num_atoms);
     inp_ATOM *cmp_mol = CreateInpAtom(num_atoms);
 
-    // int ExtractConnectedComponent(inp_ATOM *at, int num_at, int component_number, inp_ATOM *component_at)
     EXPECT_EQ(ExtractConnectedComponent(nullptr, 0, test_component_number, nullptr), 0);
 
     for (int i = 0; i < num_atoms; i++)
@@ -34,7 +33,6 @@ TEST(test_strutil, test_SetConnectedComponentNumber)
     int test_component_number = 23;
     inp_ATOM *new_mol = CreateInpAtom(num_atoms);
 
-    // int SetConnectedComponentNumber( inp_ATOM *at, int num_at, int component_number )
     EXPECT_EQ(SetConnectedComponentNumber(new_mol, num_atoms, test_component_number), 0);
 
     for (int i = 0; i < num_atoms; i++)
@@ -55,7 +53,6 @@ TEST(test_strutil, test_UnMarkRingSystemsInp)
         new_mol[i].nRingSystem = i + 1;
     }
 
-    // int UnMarkRingSystemsInp( inp_ATOM *at, int num_atoms )
     EXPECT_EQ(UnMarkRingSystemsInp(new_mol, num_atoms), 0);
 
     for (int i = 0; i < num_atoms; i++)
diff --git a/INCHI-1-TEST/tests/test_unit/test_strutil_enhancedStereo.cpp b/INCHI-1-TEST/tests/test_unit/test_strutil_enhancedStereo.cpp
new file mode 100644
index 00000000..b4b3bb0c
--- /dev/null
+++ b/INCHI-1-TEST/tests/test_unit/test_strutil_enhancedStereo.cpp
@@ -0,0 +1,262 @@
+#include <gtest/gtest.h>
+
+extern "C"
+{
+#include "../../../INCHI-1-SRC/INCHI_BASE/src/strutil.h"
+#include "../../../INCHI-1-SRC/INCHI_BASE/src/ichi_io.h"
+}
+
+TEST(test_strutil_enhancedStereo, test_set_EnhancedStereo_t_m_layers_1)
+{
+
+    INCHI_IOSTREAM input_stream;
+
+    const char *molblock =
+        "enhanc_stereo1									  \n"
+        "  ACD/LABS08242216132D                            \n"
+        "												  \n"
+        "  0  0  0  0  0  0  0  0  0  0999 V3000           \n"
+        "M  V30 BEGIN CTAB                                 \n"
+        "M  V30 COUNTS 18 17 0 0 1                         \n"
+        "M  V30 BEGIN ATOM                                 \n"
+        "M  V30 1 C 3424.1946 -1936.7935 0 0               \n"
+        "M  V30 2 C 3352.3145 -1895.2935 0 0               \n"
+        "M  V30 3 C 3280.4346 -1936.7935 0 0               \n"
+        "M  V30 4 C 3208.5542 -1895.2935 0 0               \n"
+        "M  V30 5 C 3136.6743 -1936.7935 0 0               \n"
+        "M  V30 6 C 3064.7944 -1895.2935 0 0               \n"
+        "M  V30 7 Br 3136.6743 -2019.7935 0 0              \n"
+        "M  V30 8 Cl 3208.5542 -1812.2935 0 0              \n"
+        "M  V30 9 Cl 3280.4346 -2019.7935 0 0              \n"
+        "M  V30 10 Cl 3352.3145 -1812.2935 0 0             \n"
+        "M  V30 11 Cl 3424.1946 -2019.7935 0 0             \n"
+        "M  V30 12 C 3496.075 -1895.2935 0 0               \n"
+        "M  V30 13 C 3567.9548 -1936.7942 0 0              \n"
+        "M  V30 14 C 3639.835 -1895.2944 0 0               \n"
+        "M  V30 15 C 3711.7148 -1936.7942 0 0              \n"
+        "M  V30 16 Cl 3639.835 -1812.2944 0 0              \n"
+        "M  V30 17 Cl 3567.9548 -2019.7942 0 0             \n"
+        "M  V30 18 Cl 3496.075 -1812.2937 0 0              \n"
+        "M  V30 END ATOM                                   \n"
+        "M  V30 BEGIN BOND                                 \n"
+        "M  V30 1 1 1 2                                    \n"
+        "M  V30 2 1 1 11 CFG=3                             \n"
+        "M  V30 3 1 1 12                                   \n"
+        "M  V30 4 1 2 3                                    \n"
+        "M  V30 5 1 2 10 CFG=1                             \n"
+        "M  V30 6 1 3 4                                    \n"
+        "M  V30 7 1 3 9 CFG=1                              \n"
+        "M  V30 8 1 4 5                                    \n"
+        "M  V30 9 1 4 8 CFG=1                              \n"
+        "M  V30 10 1 5 6                                   \n"
+        "M  V30 11 1 5 7 CFG=1                             \n"
+        "M  V30 12 1 12 13                                 \n"
+        "M  V30 13 1 12 18 CFG=3                           \n"
+        "M  V30 14 1 13 14                                 \n"
+        "M  V30 15 1 13 17 CFG=1                           \n"
+        "M  V30 16 1 14 15                                 \n"
+        "M  V30 17 1 14 16 CFG=1                           \n"
+        "M  V30 END BOND                                   \n"
+        "M  V30 BEGIN COLLECTION                           \n"
+        "M  V30 MDLV30/STERAC2 ATOMS=(1 1)                 \n"
+        "M  V30 MDLV30/STERAC1 ATOMS=(2 2 3)               \n"
+        "M  V30 MDLV30/STEABS ATOMS=(2 4 5)                \n"
+        "M  V30 MDLV30/STEREL1 ATOMS=(2 12 13)             \n"
+        "M  V30 MDLV30/STEREL2 ATOMS=(1 14)                \n"
+        "M  V30 END COLLECTION                             \n"
+        "M  V30 END CTAB                                   \n"
+        "M  END                                            \n";
+
+    inchi_ios_init(&input_stream, INCHI_IOS_TYPE_STRING, nullptr);
+    inchi_ios_print_nodisplay(&input_stream, molblock);
+
+    ORIG_ATOM_DATA *orig_inp_data = (ORIG_ATOM_DATA*)inchi_calloc(1, sizeof(ORIG_ATOM_DATA));
+    int bMergeAllInputStructures = 0;
+    int bGetOrigCoord = 0;
+    int bDoNotAddH = 0;
+    int treat_polymers = 0;
+    int treat_NPZz = 0;
+    const char *pSdfLabel = nullptr;
+    char *pSdfValue = nullptr;
+    unsigned long *lSdfId = nullptr;
+    long *lMolfileNumber = nullptr;
+    INCHI_MODE pInpAtomFlags = 0;
+    int err = 0;
+    char *pStrErr = nullptr;
+    int bNoWarnings = 0;
+
+    int ret = CreateOrigInpDataFromMolfile(
+        &input_stream,
+        orig_inp_data,
+        bMergeAllInputStructures,
+        bGetOrigCoord,
+        bDoNotAddH,
+        treat_polymers,
+        treat_NPZz,
+        pSdfLabel,
+        pSdfValue,
+        lSdfId,
+        lMolfileNumber,
+        &pInpAtomFlags,
+        &err,
+        pStrErr,
+        bNoWarnings);
+
+    EXPECT_EQ(ret, orig_inp_data->num_inp_atoms);
+
+    int num_at = orig_inp_data->num_inp_atoms;
+
+    int found_num_bonds = 0;
+    int found_num_isotopic = 0;
+
+    inp_ATOM *at = CreateInpAtom(num_at);
+    INChI *inchi = Alloc_INChI(at, num_at, &found_num_bonds, &found_num_isotopic, 0);
+
+    AT_NUMB at_tmp[] = {0,1,2,3,4,5,6,7,8};
+    S_CHAR parity_tmp[] = {2,1,1,2,2,1,2,2,1};
+    for (int i = 0; i < 9; i++) {
+        inchi->Stereo->nNumber[i] = at_tmp[i];
+        inchi->Stereo->t_parity[i] = parity_tmp[i];
+    }
+
+    inchi->Stereo->nNumberOfStereoCenters = 9;
+    inchi->Stereo->nCompInv2Abs = -1;
+    inchi->nNumberOfAtoms = num_at;
+
+    int nAllocMode = 0;
+    int bOrigCoord = 0;
+
+    INChI_Aux *pAux = Alloc_INChI_Aux( num_at,
+                                       0, // inp_cur_data->num_isotopic,
+                                       nAllocMode,
+                                       bOrigCoord );
+
+
+    pAux->nNumberOfAtoms = 9;
+
+    pAux->nOrigAtNosInCanonOrd[0] = 4;
+    pAux->nOrigAtNosInCanonOrd[1] = 5;
+    pAux->nOrigAtNosInCanonOrd[2] = 1;
+    pAux->nOrigAtNosInCanonOrd[3] = 2;
+    pAux->nOrigAtNosInCanonOrd[4] = 3;
+    pAux->nOrigAtNosInCanonOrd[5] = 12;
+    pAux->nOrigAtNosInCanonOrd[6] = 13;
+    pAux->nOrigAtNosInCanonOrd[7] = 14;
+
+    ret = set_EnhancedStereo_t_m_layers(orig_inp_data, inchi, pAux);
+
+    EXPECT_EQ(ret, 0);
+
+    FreeOrigAtData(orig_inp_data);
+    inchi_free(orig_inp_data);
+    Free_INChI_Aux(&pAux);
+    Free_INChI(&inchi);
+    FreeInpAtom(&at);
+
+    inchi_ios_free_str(&input_stream);
+
+}
+
+TEST(test_strutil_enhancedStereo, test_get_canonical_atom_number_1)
+{
+
+    INChI_Aux aux;
+    int n_atoms = 5;
+    AT_NUMB orig_atoms[] = {10, 20, 30, 40, 50};
+    aux.nNumberOfAtoms = n_atoms;
+    aux.nOrigAtNosInCanonOrd = orig_atoms;
+
+    // Should return 1-based canonical atom number for each original atom number
+    EXPECT_EQ(get_canonical_atom_number(&aux, 10), 1);
+    EXPECT_EQ(get_canonical_atom_number(&aux, 20), 2);
+    EXPECT_EQ(get_canonical_atom_number(&aux, 30), 3);
+    EXPECT_EQ(get_canonical_atom_number(&aux, 40), 4);
+    EXPECT_EQ(get_canonical_atom_number(&aux, 50), 5);
+
+    // Should return -1 for atom numbers not present
+    EXPECT_EQ(get_canonical_atom_number(&aux, 99), -1);
+    EXPECT_EQ(get_canonical_atom_number(&aux, 0), -1);
+
+}
+
+TEST(test_strutil_enhancedStereo, test_get_parity_idx_from_canonical_atom_number)
+{
+
+    // Example: canonical atom numbers for a molecule with 4 stereo centers
+    AT_NUMB nNumber[] = {3, 1, 4, 2};
+    int nof_atoms = 4;
+
+    // Should return the index where the canonical atom number is found
+    EXPECT_EQ(get_parity_idx_from_canonical_atom_number(3, nNumber, nof_atoms), 0);
+    EXPECT_EQ(get_parity_idx_from_canonical_atom_number(1, nNumber, nof_atoms), 1);
+    EXPECT_EQ(get_parity_idx_from_canonical_atom_number(4, nNumber, nof_atoms), 2);
+    EXPECT_EQ(get_parity_idx_from_canonical_atom_number(2, nNumber, nof_atoms), 3);
+
+    // Should return -1 for a canonical atom number not present
+    EXPECT_EQ(get_parity_idx_from_canonical_atom_number(5, nNumber, nof_atoms), -1);
+    EXPECT_EQ(get_parity_idx_from_canonical_atom_number(0, nNumber, nof_atoms), -1);
+}
+
+TEST(test_strutil_enhancedStereo, invert_parities_basic)
+{
+    // Setup INChI_Stereo
+    INChI_Stereo stereo;
+    AT_NUMB nNumber[] = {1, 2, 3};
+    S_CHAR t_parity[] = {2, 1, 2}; // 2=+, 1=-
+    stereo.nNumber = nNumber;
+    stereo.t_parity = t_parity;
+    stereo.nNumberOfStereoCenters = 3;
+    stereo.nCompInv2Abs = 1;
+
+    // Setup INChI
+    INChI inchi = {0};
+    inchi.Stereo = &stereo;
+
+    // Setup INChI_Aux
+    INChI_Aux aux = {0};
+    AT_NUMB orig_atoms[] = {1, 2, 3};
+    aux.nNumberOfAtoms = 3;
+    aux.nOrigAtNosInCanonOrd = orig_atoms;
+
+    // Setup list_atoms: one group, 3 atoms (original numbers 1,2,3)
+    int group1[] = {0, 3, 1, 2, 3}; // [unused, n_atoms, orig_atom1, orig_atom2, orig_atom3]
+    int* lists[1] = {group1};
+
+    // Call invert_parities for absolute group
+    int ret = invert_parities(&inchi, &aux, lists, 1, 1);
+
+    EXPECT_EQ(ret, 0);
+
+    EXPECT_EQ(stereo.t_parity[0], 1);
+    EXPECT_EQ(stereo.t_parity[1], 2);
+    EXPECT_EQ(stereo.t_parity[2], 1);
+
+    EXPECT_EQ(stereo.nCompInv2Abs, -1);
+
+    t_parity[0] = 2;
+    t_parity[1] = 1;
+    t_parity[2] = 2;
+
+    stereo.nCompInv2Abs = 1;
+
+    ret = invert_parities(&inchi, &aux, lists, 1, 0);
+
+    EXPECT_EQ(ret, 0);
+
+    EXPECT_EQ(stereo.t_parity[0], 1);
+    EXPECT_EQ(stereo.t_parity[1], 2);
+    EXPECT_EQ(stereo.t_parity[2], 1);
+
+    EXPECT_EQ(stereo.nCompInv2Abs, 1);
+
+    ret = invert_parities(&inchi, &aux, lists, 1, 0);
+
+    EXPECT_EQ(ret, 0);
+
+    EXPECT_EQ(stereo.t_parity[0], 1);
+    EXPECT_EQ(stereo.t_parity[1], 2);
+    EXPECT_EQ(stereo.t_parity[2], 1);
+
+    EXPECT_EQ(stereo.nCompInv2Abs, 1);
+}
+
diff --git a/INCHI-1-TEST/tests/test_unit/test_util.cpp b/INCHI-1-TEST/tests/test_unit/test_util.cpp
index 037caa99..f4eb26ca 100644
--- a/INCHI-1-TEST/tests/test_unit/test_util.cpp
+++ b/INCHI-1-TEST/tests/test_unit/test_util.cpp
@@ -978,19 +978,3 @@ TEST(test_util, test_extract_stereo_info_from_inchi_string)
 
     EXPECT_EQ(found_stereo2, 0);
 }
-
-// TEST(test_util, test_extract_all_backbone_bonds_from_inchi_string)
-// {
-
-//     // int extract_all_backbone_bonds_from_inchi_string(char *sinchi, int *n_all_bkb_orig, int *orig, int *all_bkb_orig);
-
-//     char inchi1[] = "InChI=1S/C2H6/c1-2/h1-2H3";
-
-//     int n_all_bkb_orig[2] = {0, 0};
-//     int orig[2] = {0, 1};
-//     int all_bkb_orig[2] = {0, 0};
-
-//     int ret1 = extract_all_backbone_bonds_from_inchi_string(inchi1, n_all_bkb_orig, orig, all_bkb_orig);
-
-//     EXPECT_EQ(ret1, 0);
-// }