peterspackman · peterspackman · Jan 13, 2026 · Nov 7, 2025 · Nov 7, 2025 · Nov 7, 2025
diff --git a/.gitignore b/.gitignore
@@ -18,6 +18,7 @@ occjs.js
 occjs.wasm
 wasm/
 examples/*
+CMakeFiles/
 
 # Node.js
 node_modules/

diff --git a/3rdparty/CMakeLists.txt b/3rdparty/CMakeLists.txt
@@ -1,3 +1,5 @@
+set(CMAKE_UNITY_BUILD OFF)
+
 CPMAddPackage(
     NAME fmt
     GITHUB_REPOSITORY "fmtlib/fmt"

diff --git a/CMakeLists.txt b/CMakeLists.txt
@@ -19,9 +19,42 @@ endif()
 set(CMAKE_MODULE_PATH ${CMAKE_CURRENT_SOURCE_DIR}/cmake)
 
 if(SKBUILD)
-  set(WITH_PYTHON_BINDINGS ON)
+    set(WITH_PYTHON_BINDINGS ON)
 endif()
 
+# Build acceleration options
+option(WITH_CCACHE "Use ccache for faster clean rebuilds (if available)" ON)
+option(WITH_UNITY_BUILD "Enable unity builds (faster clean builds, slower incremental)" OFF)
+
+# lld is faster on Linux but incompatible with Apple clang on macOS
+if(NOT APPLE)
+    option(WITH_LLD "Use lld linker for faster linking (if available)" ON)
+else()
+    option(WITH_LLD "Use lld linker for faster linking (if available)" OFF)
+endif()
+
+if(WITH_CCACHE)
+    find_program(CCACHE_PROGRAM ccache)
+    if(CCACHE_PROGRAM)
+        message(STATUS "Using ccache: ${CCACHE_PROGRAM}")
+        set(CMAKE_C_COMPILER_LAUNCHER "${CCACHE_PROGRAM}")
+        set(CMAKE_CXX_COMPILER_LAUNCHER "${CCACHE_PROGRAM}")
+    endif()
+endif()
+
+if(WITH_LLD)
+    find_program(LLD_PROGRAM lld)
+    if(LLD_PROGRAM)
+        message(STATUS "Using lld linker: ${LLD_PROGRAM}")
+        add_link_options("-fuse-ld=lld")
+    endif()
+endif()
+
+if(WITH_UNITY_BUILD)
+    message(STATUS "Unity builds enabled")
+    set(CMAKE_UNITY_BUILD ON)
+    set(CMAKE_UNITY_BUILD_BATCH_SIZE 8)
+endif()
 
 if(CMAKE_PROJECT_NAME STREQUAL PROJECT_NAME)
     include(CTest)

diff --git a/include/occ/cg/neighbor_atoms.h b/include/occ/cg/neighbor_atoms.h
@@ -1,5 +1,4 @@
 #pragma once
-#include <occ/core/linear_algebra.h>
 #include <occ/crystal/crystal.h>
 namespace occ::cg {
 

diff --git a/include/occ/cg/solvation_contribution.h b/include/occ/cg/solvation_contribution.h
@@ -1,5 +1,4 @@
 #pragma once
-#include <utility>
 
 namespace occ::cg {
 

diff --git a/include/occ/cg/solvation_types.h b/include/occ/cg/solvation_types.h
@@ -2,9 +2,7 @@
 #include <occ/cg/neighbor_atoms.h>
 #include <occ/cg/solvation_contribution.h>
 #include <occ/cg/solvent_surface.h>
-#include <occ/core/linear_algebra.h>
-#include <string>
-#include <vector>
+
 
 namespace occ::cg {
 

diff --git a/include/occ/core/eeq.h b/include/occ/core/eeq.h
@@ -1,3 +1,4 @@
+#pragma once
 
 #include <occ/core/linear_algebra.h>
 

diff --git a/include/occ/core/molecular_axis.h b/include/occ/core/molecular_axis.h
@@ -1,5 +1,4 @@
 #pragma once
-#include <occ/core/linear_algebra.h>
 #include <occ/qm/wavefunction.h>
 #include <string>
 #include <vector>

diff --git a/include/occ/core/molecule.h b/include/occ/core/molecule.h
@@ -2,7 +2,6 @@
 #include <array>
 #include <occ/core/atom.h>
 #include <occ/core/element.h>
-#include <occ/core/linear_algebra.h>
 #include <tuple>
 
 namespace occ::core {

diff --git a/include/occ/core/optimize.h b/include/occ/core/optimize.h
@@ -1,5 +1,4 @@
 #pragma once
-#include <functional>
 #include <occ/core/log.h>
 
 namespace occ::core::opt {

diff --git a/include/occ/core/point_charge.h b/include/occ/core/point_charge.h
@@ -1,7 +1,6 @@
 #pragma once
 #include <array>
 #include <occ/core/atom.h>
-#include <occ/core/linear_algebra.h>
 
 namespace occ::core {
 

diff --git a/include/occ/core/util.h b/include/occ/core/util.h
@@ -4,7 +4,6 @@
 #include <chrono>
 #include <fmt/core.h>
 #include <fmt/ostream.h>
-#include <locale>
 #include <numeric>
 #include <occ/core/linear_algebra.h>
 #include <string>

diff --git a/include/occ/core/vibration.h b/include/occ/core/vibration.h
@@ -1,5 +1,4 @@
 #pragma once
-#include <occ/core/linear_algebra.h>
 #include <occ/core/molecule.h>
 #include <vector>
 #include <string>

diff --git a/include/occ/crystal/crystal.h b/include/occ/crystal/crystal.h
@@ -1,7 +1,6 @@
 #pragma once
 #include <occ/core/bondgraph.h>
 #include <occ/core/dimer.h>
-#include <occ/core/linear_algebra.h>
 #include <occ/core/molecule.h>
 #include <occ/crystal/asymmetric_unit.h>
 #include <occ/crystal/hkl.h>

diff --git a/include/occ/dft/seminumerical_exchange.h b/include/occ/dft/seminumerical_exchange.h
@@ -1,10 +1,8 @@
 #pragma once
 #include <occ/core/atom.h>
-#include <occ/core/linear_algebra.h>
 #include <occ/dft/molecular_grid.h>
 #include <occ/qm/integral_engine.h>
-#include <occ/qm/mo.h>
-#include <vector>
+
 
 namespace occ::dft::cosx {
 

diff --git a/include/occ/driver/crystal_growth.h b/include/occ/driver/crystal_growth.h
@@ -5,7 +5,6 @@
 #include <occ/cg/solvation_contribution.h>
 #include <occ/cg/solvent_surface.h>
 #include <occ/core/dimer.h>
-#include <occ/core/log.h>
 #include <occ/core/molecule.h>
 #include <occ/core/point_group.h>
 #include <occ/core/timings.h>
@@ -14,7 +13,6 @@
 #include <occ/interaction/pair_energy.h>
 #include <occ/interaction/pairinteraction.h>
 #include <occ/io/wavefunction_json.h>
-#include <occ/qm/wavefunction.h>
 
 namespace occ::driver {
 

diff --git a/include/occ/driver/dma_driver.h b/include/occ/driver/dma_driver.h
@@ -1,5 +1,4 @@
 #pragma once
-#include <occ/core/log.h>
 #include <occ/dma/dma.h>
 #include <occ/qm/wavefunction.h>
 #include <ankerl/unordered_dense.h>

diff --git a/include/occ/elastic_fit/elastic_fitting.h b/include/occ/elastic_fit/elastic_fitting.h
@@ -2,8 +2,7 @@
 #include <occ/core/dimer.h>
 #include <occ/elastic_fit/pes.h>
 #include <occ/interaction/interaction_json.h>
-#include <string>
-#include <vector>
+
 
 namespace occ::elastic_fit {
 

diff --git a/include/occ/elastic_fit/monkhorst_pack.h b/include/occ/elastic_fit/monkhorst_pack.h
@@ -1,3 +1,4 @@
+#pragma once
 #include <occ/core/linear_algebra.h>
 
 namespace occ::elastic_fit {

diff --git a/include/occ/elastic_fit/pes.h b/include/occ/elastic_fit/pes.h
@@ -120,26 +120,9 @@ class PES {
     }
   }
 
-  static inline occ::Mat solve_linear_system(const occ::Mat &A,
-                                             const occ::Mat &B,
-                                             LinearSolverType solver_type,
-                                             double svd_threshold = 1e-12) {
-    switch (solver_type) {
-    case LinearSolverType::LU:
-      return A.lu().solve(B);
-    case LinearSolverType::SVD: {
-      Eigen::JacobiSVD<occ::Mat> svd(A,
-                                     Eigen::ComputeThinU | Eigen::ComputeThinV);
-      return svd.solve(B);
-    }
-    case LinearSolverType::QR:
-      return A.householderQr().solve(B);
-    case LinearSolverType::LDLT:
-      return A.ldlt().solve(B);
-    default:
-      throw std::runtime_error("Unknown linear solver type");
-    }
-  }
+  static occ::Mat solve_linear_system(const occ::Mat &A, const occ::Mat &B,
+                                      LinearSolverType solver_type,
+                                      double svd_threshold = 1e-12);
 };
 
 } // namespace occ::elastic_fit
diff --git a/include/occ/elastic_fit/potentials.h b/include/occ/elastic_fit/potentials.h
@@ -1,11 +1,9 @@
 #pragma once
 #include <cmath>
-#include <occ/core/linear_algebra.h>
 #include <occ/core/log.h>
 #include <occ/crystal/crystal.h>
 #include <stdexcept>
-#include <string>
-#include <vector>
+
 
 namespace occ::elastic_fit {
 

diff --git a/include/occ/geometry/index_cache.h b/include/occ/geometry/index_cache.h
@@ -1,8 +1,8 @@
+#pragma once
 #include <Eigen/Core>
 #include <array>
 #include <cstddef>
 #include <cstdint>
-#include <vector>
 
 namespace occ::geometry {
 

diff --git a/include/occ/interaction/energy_model_base.h b/include/occ/interaction/energy_model_base.h
@@ -1,5 +1,4 @@
 #pragma once
-#include <occ/core/dimer.h>
 #include <occ/interaction/pair_energy.h>
 
 namespace occ::interaction {

diff --git a/include/occ/io/cifparser.h b/include/occ/io/cifparser.h
@@ -1,11 +1,8 @@
 #pragma once
 #include <ankerl/unordered_dense.h>
 #include <gemmi/cif.hpp>
-#include <iostream>
-#include <map>
 #include <occ/crystal/crystal.h>
 #include <occ/io/occ_input.h>
-#include <regex>
 #include <string>
 
 namespace occ::io {

diff --git a/include/occ/io/fchkwriter.h b/include/occ/io/fchkwriter.h
@@ -1,13 +1,10 @@
 #pragma once
 #include <ankerl/unordered_dense.h>
-#include <array>
 #include <fstream>
-#include <istream>
 #include <occ/core/linear_algebra.h>
 #include <occ/qm/shell.h>
 #include <occ/qm/spinorbital.h>
 #include <variant>
-#include <vector>
 
 namespace occ::io {
 

diff --git a/include/occ/io/moldenreader.h b/include/occ/io/moldenreader.h
@@ -5,7 +5,6 @@
 #include <occ/qm/spinorbital.h>
 #include <optional>
 #include <string>
-#include <vector>
 
 namespace occ::io {
 

diff --git a/include/occ/io/occ_input.h b/include/occ/io/occ_input.h
@@ -7,7 +7,6 @@
 #include <occ/crystal/crystal.h>
 #include <occ/io/grid_settings.h>
 #include <occ/qm/spinorbital.h>
-#include <vector>
 
 namespace occ::io {
 using occ::core::Element;

diff --git a/include/occ/io/orca_json.h b/include/occ/io/orca_json.h
@@ -2,7 +2,6 @@
 #include <fstream>
 #include <istream>
 #include <occ/core/atom.h>
-#include <occ/core/linear_algebra.h>
 #include <occ/qm/shell.h>
 #include <occ/qm/spinorbital.h>
 #include <string>

diff --git a/include/occ/isosurface/point_functors.h b/include/occ/isosurface/point_functors.h
@@ -62,8 +62,8 @@ struct PromolDensityFunctor {
   std::vector<pfimpl::AtomInterpolator> atom_interpolators;
 };
 
-struct ElectronDensityFunctor {
-  ElectronDensityFunctor(const Wavefunction &wfn,
+struct Point_ElectronDensityFunctor {
+  Point_ElectronDensityFunctor(const Wavefunction &wfn,
                          SpinConstraint spin = SpinConstraint::Total);
   void operator()(Eigen::Ref<const Mat3N> points, Eigen::Ref<Vec> dest);
 
@@ -72,13 +72,13 @@ struct ElectronDensityFunctor {
   int mo_index{-1};
 };
 
-struct DeformationDensityFunctor {
-  DeformationDensityFunctor(const Wavefunction &wfn,
+struct Point_DeformationDensityFunctor {
+  Point_DeformationDensityFunctor(const Wavefunction &wfn,
                             SpinConstraint = SpinConstraint::Total);
   void operator()(Eigen::Ref<const Mat3N> points, Eigen::Ref<Vec> dest);
 
   PromolDensityFunctor pro_func;
-  ElectronDensityFunctor rho_func;
+  Point_ElectronDensityFunctor rho_func;
 };
 
 struct XCDensityFunctor {

diff --git a/include/occ/main/occ_elastic_fit.h b/include/occ/main/occ_elastic_fit.h
@@ -1,6 +1,5 @@
 #pragma once
 #include <CLI/App.hpp>
-#include <occ/crystal/crystal.h>
 #include <occ/elastic_fit/monkhorst_pack.h>
 #include <occ/elastic_fit/pes.h>
 #include <occ/elastic_fit/potentials.h>

diff --git a/include/occ/qm/cint_interface.h b/include/occ/qm/cint_interface.h
@@ -146,17 +146,9 @@ class IntegralEnvironment {
     }
   }
 
-  void set_common_origin(const std::array<double, 3> &origin) {
-    m_env_data[libcint::common_origin_offset] = origin[0];
-    m_env_data[libcint::common_origin_offset + 1] = origin[1];
-    m_env_data[libcint::common_origin_offset + 2] = origin[2];
-  }
+  void set_common_origin(const std::array<double, 3> &origin);
 
-  void set_rinv_origin(const std::array<double, 3> &origin) {
-    m_env_data[libcint::rinv_origin_offset] = origin[0];
-    m_env_data[libcint::rinv_origin_offset + 1] = origin[1];
-    m_env_data[libcint::rinv_origin_offset + 2] = origin[2];
-  }
+  void set_rinv_origin(const std::array<double, 3> &origin);
 
   void set_rinv_zeta(double zeta) {
     m_env_data[libcint::rinv_zeta_offset] = zeta;
@@ -556,25 +548,8 @@ class IntegralEnvironment {
     m_env_data[libcint::range_omega_offset] = omega;
   }
 
-  inline void print() const {
-    fmt::print("Atom Info {}\n", m_atom_info.size());
-    for (const auto &atom : m_atom_info) {
-      fmt::print("{} {} {} {} {} {}\n", atom.data[0], atom.data[1],
-                 atom.data[2], atom.data[3], atom.data[4], atom.data[5]);
-    }
-    fmt::print("Basis Info {}\n", m_basis_info.size());
-    for (const auto &sh : m_basis_info) {
-      fmt::print("{} {} {} {} {} {}\n", sh.data[0], sh.data[1], sh.data[2],
-                 sh.data[3], sh.data[4], sh.data[5], sh.data[6], sh.data[7]);
-    }
-    fmt::print("Env Data {}\n", m_env_data.size());
-    for (size_t i = 0; i < m_env_data.size(); i++) {
-      fmt::print("{:12.6f} ", m_env_data[i]);
-      if (i > 0 && (i % 6 == 0))
-        fmt::print("\n");
-    }
-    fmt::print("\n");
-  }
+  void print() const ;
+
 
   inline size_t buffer_size_1e(const Operator op = Operator::overlap,
                                int grad = 0) const {

diff --git a/include/occ/qm/integral_engine.h b/include/occ/qm/integral_engine.h
@@ -1,18 +1,13 @@
 #pragma once
-#include <array>
-#include <occ/core/atom.h>
 #include <occ/core/log.h>
-#include <occ/core/multipole.h>
 #include <occ/core/parallel.h>
 #include <occ/core/timings.h>
 #include <occ/qm/cint_interface.h>
 #include <occ/qm/expectation.h>
 #include <occ/qm/mo.h>
-#include <occ/qm/shell.h>
 #include <occ/qm/shellblock_norm.h>
-#include <optional>
 #include <unsupported/Eigen/CXX11/Tensor>
-#include <vector>
+
 
 #if HAVE_ECPINT
 #include <libecpint.hpp>
Original file line number	Diff line number	Diff line change
		@@ -1,3 +1,4 @@
		#pragma once

		#include <occ/core/linear_algebra.h>

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