AbInTM.bib

@article{00Haxxxx.Re,
  title={Electronic structure of diatomic molecules composed of a first-row transition metal and main-group element (HF)},
  author={Harrison, James F},
  journal={Chem. Rev.},
  volume={100},
  pages={679--716},
  year={2000},
}

@article{00KaMaxx.Re,
	Abstract = {The CrB+ cation molecular system has been investigated with the help of semi-quantitative basis sets [(7s6p4d3f)Cr/(4s3p2d1f)B] and highly correlated (valence) multi-reference wave functions. Out of a possible manifold of 70 states correlating to the Cr+(6S,6D, 4D, 4G)+B(2P) atomic states, we have explored a total of 35 states spanning an energy range of about 3.4 eV. The ground state is of X 7Sigma+ symmetry with a binding energy of 28.8 kcal/mol at an internuclear distance of 2.242 {\AA}. The next three excited states 1 5Sigma+, 2 5Pi, and 37Pi with energy splittings 7.1, 12.9, and 24.3 kcal/mol from the X state, have binding energies of 21.8, 16.5, and 5.1 kcal/mol, respectively. For practically all states we report potential energy curves, total energies, the most common spectroscopic parameters, while we discuss the binding modes using simple chemical diagrams based on valence-bond concepts. },
	Author = {Kalemos, Apostolos and Mavridis, Aristides},
	Journal = JCP,
	Pages = {2270--2281},
	Title = {Electronic structure determination of chromium boride cation, CrB+},
	Volume = {113},
	Year = {2000}}

@article{04BoMaxx.Re,
	Abstract = {A multireference configuration interaction (MRCI) approach, based on complete-active-space self-consistent-field (CASSCF) wave functions, with extended basis sets such as Watchers' (14s 11p 6d 3f)/[8s 6p 4d 1f] for nickel and correlation-consistent polarized-valence triple-zeta (cc-pVTZ) for carbon, were employed to revise the lowest-lying singlet and triplet electronic states of NiC. The energetic ordering (Te values in parenthesis) of the electronic states, X1Σ+, a3Π (7882 cm−1), A1Π (9427 cm−1), B1Φ (10 156 cm−1), b3Φ (10 689 cm−1), C3Σ+ (10 835 cm−1), C1Δ (14 352 cm−1), and d3Δ (14 363 cm−1), was found to be in variance with that obtained previously at the \{CASSCF\} level, re-emphasizing the need of including nondynamical and dynamic correlations effects into the wave function of systems containing transition metals. },
	Author = {Antonio Carlos Borin and Luiz Guilherme M {de Macedo}},
	Doi = {http://dx.doi.org/10.1016/j.cplett.2003.11.002},

	Journal = CPL,
	Pages = {53 - 58},
	Title = {The lowest singlet and triplet electronic states of NiC revised},
	Volume = {383},
	Year = {2004}}

@article{05AbAlKo.Re,
	Abstract = {CAS-SCF/MRCI calculations have been performed for 15 molecular states in the representation 2S+1Λ(+/−) (neglecting spin--orbit effects) for the molecule YI. The corresponding 33 molecular states in the representation Ω(+/−) (including spin--orbit effects) have been calculated using a semi-empirical spin--orbit pseudopotential built up for yttrium. Calculated potential energy curves and spectroscopic constants are reported, to the best of our knowledge they are the first ones from ab initio methods for this molecule. Present results are compared to experimental accurate data available for the ground X1Σ+ and 3 excited states (1)1Π, (2)1Σ+ and (2)1Π. },
	Author = {S. Abdul-Al and A. R. Allouche and M. Korek and M. Aubert-Fr{\'e}con},
	Doi = {http://dx.doi.org/10.1016/j.chemphys.2004.07.032},
	Journal = CP,
	Pages = {1 - 6},
	Title = {Theoretical electronic structure of the lowest-lying states of the \{YI\} molecule},
	Volume = {308},
	Year = {2005}}

@article{06GaYaRe.Re,
	Abstract = {The multireference configuration interaction (MRCI) method is used to calculate a set of energies at different internuclear distances and six different computational levels. Six potential energy curves (PECs) are obtained. Four of them are fitted to analytical potential energy functions (APEFs) using the Murrel-Sorbie potential function, because the dissociation energies and bond lengths of the other ones are obviously not in agreement with the experimental values. Based on the PECs, the vibrational levels are determined by solving Schr{\"o}dinger equation of nuclear motion, and corresponding spectroscopic parameters are accurately calculated respectively. The values of equilibrium positions and dissociation energies we obtained are compared with other theory and experimental data available at present. },
	Author = {Feng Gao and Chuan-Lu Yang and Ting-Qi Ren},
	Doi = {http://dx.doi.org/10.1016/j.theochem.2005.10.030},
	Issn = {0166-1280},
	Journal = JMS,
	Pages = {81 - 85},
	Title = {\{MRCI\} potential curve and analytical potential energy function of the ground state (1Σ+) of HgZn},
	Volume = {758},
	Year = {2006}}

@article{06MiBeBa.Re,
	Abstract = {Spectroscopic constants and molecular properties of CuO and CuS in their ground state have been studied in detail using B3LYP, \{MP2\} and CCSD(T) methods. The basis set has been designed by testing the convergence and consistency of the calculated spectroscopic properties of these molecules and the final basis set is used for this calculation. The basis set of Cu (7s6p4d2f) has been built upon the basis set (6s3p3d) of Ahlrichs et al. and the basis sets for oxygen and sulfur are correlation consistent basis set. The spectroscopic properties of CuO and CuS obtained with CCSD(T) method in conjunction with these basis sets agree well with the experimental values wherever available for comparison. Most of the spectroscopic properties of CuO and CuS are new. The spectroscopic properties of CuS are first reported theoretically. },
	Author = {S. Midda and N. C. Bera and I. Bhattacharyya and A. K. Das},
	Doi = {http://dx.doi.org/10.1016/j.theochem.2005.12.003},
	Journal = JMS,
	Pages = {17 - 20},
	Title = {Ab initio and density functional study of spectroscopic properties of CuO and CuS},
	Volume = {761},
	Year = {2006}}

@article{06Raxxxx.Re,
	Abstract = {A comprehensive analysis on the successes and failures of the theoretical spectroscopy of copper and silver monohalides is presented in light of the recent theoretical versus experimental information for these systems. It is shown that although for copper monohalides the standard quantum chemical multireference SCF, perturbational or CI approaches work well to describe their spectroscopy, for their silver counterparts this is not the case always. While density functional theory is intrinsically unable to deal with the most intense transition (B1∑+-X1∑+) observed in the whole CuX and AgX series, the CASSCF+CASPT2 method fails for the AgX family is describing this excitation, even with the largest physically meaningful valence orbital active space. The complexity of silver halides arises from the concatenation of three independent problems: first, the isolated atom spectroscopy is much more complex for Ag than for Cu, since for silver the Rydberg 2P(4d 105p 1) state lies close but below the valence 2 D(4d 95s 2) one; secondly, the spin-orbit coupling for silver is much larger and thus the fine-structure components of these doublets are intertwined, leading to very large ΛS∑ mixing effects in the molecular case. Finally, rather strong interactions exist between the numerous Ag(4d 95s 2)X(np 5) and Ag(4d 105p 1)X(np 5) neutral configurations with the Ag+(4d 95s1)X -(np 6) ionic structures, making the accurate description of these mixtures an extremely difficult task, especially for the second 1∑+ state, where even large CASSCF calculations fail at providing continuous state-specific potential energy curves. This remains a true theoretical impasse related to the still unsolved and complex convergence for the coupled CI-orbital multivariate minimization problem. Therefore, it is only possible to properly describe the electronic structure of the excited states of silver monohalides using the full valence active space, to perform variational treatments of the non-dynamic and dynamic electronic correlation treatments with especially optimized and extended RECP-basis sets; then the spin-orbit effects must imperatively be taken into account to qualitatively explain the nature of the observed AgX spectra. However, non-negligible errors are found for some of the basic spectroscopic quantities such as transition energies and vibrational frequencies for the most spectroscopically active excited states.},
	Author = {Ram{\'\i}rez-Sol{\'\i}s, A.},
	Document_Type = {Article},
	Doi = {10.1007/s00214-006-0110-8},
	Journal = TCA,
	Pages = {641-654},
	Title = {The spectroscopy of copper and silver monohalides: What modern quantum chemistry can and cannot do},
	Volume = {116},
	Year = {2006}}

@article{07DeCeTh.Re,
	Abstract = {Spectroscopic constants of the two lowest states of the InN molecule, the X3Σ− ground and the 3Π excited state were calculated using the restricted open-shell Hartree--Fock Coupled Cluster ROHF-CCSD(T) method with single, double and perturbative triples, the complete active space second-order perturbation theory (CASPT2) and the multireference configuration interaction (MRDCI) methods. Relativistic pseudopotentials (for MRDCI) and atomic natural orbital basis set for treating spin--orbit and scalar relativistic effects -- ANO-RCC (for CCSD(T), \{CASPT2\} and CASPT2/RASSI-SO) were used. The accuracy of different methods was compared correlating up to 26 valence and core-valence electrons of N and In atoms. },
	Author = {Luk{\'a}{\v s} Demovi{\v c} and Ivan {\v C}ernu{\v s}{\'a}k and Giannoula Theodorakopoulos and Ioannis D. Petsalakis and Miroslav Urban},
	Doi = {http://dx.doi.org/10.1016/j.cplett.2007.09.035},
	Journal = CPL,
	Pages = {215 - 220},
	Title = {Improved theoretical calculations of InN in its X3Σ− ground state and in the first 3Π excited state},
	Volume = {447},
	Year = {2007}}

@article{07GhBoMa.Re,
	Abstract = {Using an ab initio approach involving a non-empirical pseudopotentials for Na and Rb atoms, the adiabatic potential energy curves of 26 electronic states of NaRb+ ionic molecule dissociating up to Na(4p) + Rb+ and Na+ + Rb(7s) have been investigated. Their molecular spectroscopic constants have been derived and compared with the available theoretical works. Furthermore, the transition dipole moments from X2Σ+ and 22Σ+ to higher excited states have been determined. Numerous avoided crossings between electronic states of 2Σ+ and 2Π symmetries have been localised and analysed. Their existences are related to the charge transfer process between the two ionic systems Na+Rb and NaRb+. The accurate potential energy curves have been exploited to realize a long-range vibrational level spacing analysis using the \{WKB\} semi-classical approximation in order to extract the Na and Rb atomic static dipole polarizabilities. A very good agreement between our static dipole polarizabilities and the available experimental and theoretical works has been observed. },
	Author = {C. Ghanmi and H. Bouzouita and N. Mabrouk and H. Berriche},
	Doi = {http://dx.doi.org/10.1016/j.theochem.2006.12.029},
	Journal = JMS,
	Pages = {1 - 7},
	Title = {Ab initio study of NaRb+: Potential energy curves, spectroscopic constants and atomic polarizabilities},
	Volume = {808},
	Year = {2007}}

@article{07ZhYaGa.Re,
	Abstract = {The multi-reference configuration interaction (MRCI) method and effective-core-potential (ECP) basis set have been used to calculate the equilibrium geometries, dissociation energies and potential energy curves (PECs) of nine states of Lu2 dimer. The analytical potential energy functions (APEFs) of these states have been fitted using Murrell--Sorbie (MS) function and least square fitting method. Based on this, the spectroscopic parameters of each state are calculated and are compared with the theoretical and the experimental values available at present. The ground state of this dimer is determined by considering both the total energy and the spectroscopic parameters. The vibrational levels for each state of Lu2 are determined by solving Schr{\"o}dinger equation of nuclear motion. },
	Author = {Xiao-Yan Zhang and Chuan-Lu Yang and Feng Gao and Ting-Qi Ren},
	Doi = {http://dx.doi.org/10.1016/j.theochem.2007.04.004},
	Journal = JMS,
	Pages = {97 - 102},
	Title = {\{MRCI\} study on the ground and low-lying excited states of lutetium dimer},
	Volume = {816},
	Year = {2007}}

@article{08KoMaxx.Re,
	Abstract = {The late-3d transition-metal diatomic fluorides MF = FeF, CoF, NiF, and CuF have been studied using variational multireference (MRCI) and coupled-cluster [RCCSD(T)] methods, combined with large to very large basis sets. We examined a total of 35 2S+1|Λ| states, constructing as well 29 full potential energy curves through the MRCI method. All examined states are ionic, diabatically correlating to M+H-F-(1S). Notwithstanding the "eccentric" character of the 3d transition metals and the difficulties to accurately be described with all-electron ab initio methods, our results are, in general, in very good agreement with available experimental numbers. {\copyright} 2008 American Chemical Society.},
	Affiliation = {Laboratory of Physical Chemistry, Department of Chemistry, National and Kapodistrian University of Athens, P.O. Box 64 004, 15710 Zografou, Athens, Greece},
	Author = {Koukounas, C. and Mavridis, A.},
	Document_Type = {Article},
	Doi = {10.1021/jp805034w},
	Journal = JPCA,
	Pages = {11235-11250},
	Title = {Ab initio study of the diatomic fluorides FeF, CoF, NiF, and CuF},
	Volume = {112},
	Year = {2008}}

@article{08RiRoOr.Re,
	Abstract = {Accurate potential energy curves, dissociation energies and spectroscopic constants for several low-lying doublet and quartet electronic states of CaAl were investigated using the CASSCF/MRCI methodology, and the cc-pVQZ basis set. Our results represent an improvement over a previous theoretical description, and also characterizes new higher excited states not previously investigated, thus confirming the assignment of four excited states investigated experimentally. With the theoretical transition moment functions, transition probabilities and radiative lifetimes were estimated via Einstein spontaneous emission coefficients. },
	Author = {Vladir W. Ribas and Orlando Roberto-Neto and Fernando R. Ornellas and Francisco B.C. Machado},
	Doi = {http://dx.doi.org/10.1016/j.cplett.2008.06.041},
	Journal = CPL,
	Pages = {411 - 416},
	Title = {Excited states of the CaAl molecule: An \{MRCI\} study},
	Volume = {460},
	Year = {2008}}

@article{09GaYaWa.Re,
	Abstract = {The multireference configuration interaction (MRCI) electronic energy calculations with different basis sets have been performed on the ground state (X1Σ) and three low-lying excited states (3Σ, 1Π and 3Π) of HgCd dimer. The obtained potential energy curves (PECs) are fit to analytical potential energy functions (APEFs) using the Murrell--Sorbie potential function. Spectroscopic constants are calculated using the APEFs. Based on the PECs, the vibrational levels of each state are predicted. Our equilibrium positions of the X1Σ state and 3Π state are in excellent agreement with the experimental reports. },
	Author = {Feng Gao and Chuan-Lu Yang and Ji-Hua Wang and Ji-Fan Hu},
	Doi = {http://dx.doi.org/10.1016/j.theochem.2009.09.005},
	Journal = JMS,
	Pages = {193 - 197},
	Title = {\{MRCI\} potential energy curves and spectroscopic constants of the ground and low-lying excited states of HgCd},
	Volume = {915},
	Year = {2009}}

@article{10CaWiCi.Re,
	Abstract = {A systematic investigation of low-lying states of Sc2 using multireference perturbation theory (NEVPT2 and NEVPT3) indicates that the ground state of this system is Σ5−u with re=2.611{\AA}, ωe=241.8cm−1, and De=1.78eV. This state is closely followed by other low-lying states of Sc2: Σ3−u, Δ5u, Π3g, Π1g, and Σ1−u. Our energy ordering of the Σ5−u and Σ3−u states confirms the recent MRCI results of Kalemos et al. [J. Chem. Phys.132, 024309 (2010)] and is at variance with the earlier diffusion Monte Carlo predictions of Matxain et al. [J. Chem. Phys.128, 194315 (2008)]. An excellent agreement between the second- and third-order NEVPT results and between the computed and experimental values of ωe (241.8 versus 238.9cm−1) for the Σ5−u state suggests high accuracy of our predictions.},
	Author = {Camacho, Cristopher and Witek, Henryk A. and Cimiraglia, Renzo},
	Doi = {http://dx.doi.org/10.1063/1.3442374},
	Journal = JCP,
	Pages = {244306},
	Title = {The low-lying states of the scandium dimer},
	Volume = {132},
	Year = {2010}}

@article{10KaKaMa.Re,
	Author = {Kalemos, Apostolos and Kaplan, Ilya G and Mavridis, Aristides},
	Journal = JCP,
	Pages = {024309},
	Title = {The Sc2 dimer revisited},
	Volume = {132},
	Year = {2010}}

@article{10SaPaMa.Re,
	Abstract = { The species ZnO and ZnO$\pm$ have been studied by variational multireference and coupled-cluster [RCCSD(T)] methods employing augmented basis sets of quintuple cardinality. Full potential energy curves are reported for 13, 10, and 2 bound states of ZnO, ZnO+, and ZnO−, respectively. All our results are in excellent agreement with existing experimental findings. },
	Author = {Sakellaris, Constantine N. and Papakondylis, Aristotle and Mavridis, Aristides},
	Doi = {10.1021/jp104764d},
	Journal = JPCA,
	Pages = {9333-9341},
	Title = {{Ab initio Study of the Electronic Structure of Zinc Oxide and its Ions, ZnO0,$\pm$. Ground and Excited States}},
	Volume = {114},
	Year = {2010}}

@article{11Paxxxx.Re,
	Abstract = {The electronic structure of the ground and excited states of the ZnS species has been investigated by variational multireference and, in some cases, coupled-cluster techniques employing augmented basis sets of quintuple-ζ quality. Full potential energy curves are reported for 18 states. The nature of the bonding for the lowest electronic states is discussed in some detail. },
	Author = {Aristotle Papakondylis},
	Doi = {http://dx.doi.org/10.1016/j.cplett.2011.07.009},
	Issn = {0009-2614},
	Journal = CPL,
	Pages = {44 - 48},
	Title = {{Ab initio study of the ground and excited states of the zinc sulfide diatomic system, ZnS}},
	Volume = {512},
	Year = {2011}}

@article{11ShLiSu.Re,
	Abstract = {The potential energy curves (PECs) of six low-lying electronic states (X1Σ+, a3Σ+, b3Π, A1Π, 13Σ− and 15Σ+) of GeS molecule have been investigated employing the full valence complete active space self-consistent field (CASSCF) method followed by the highly accurate valence internally contracted multireference configuration interaction (MRCI) approach with large correlation-consistent basis sets for internuclear separations from 0.08 to 2.00 nm. The effects on the spectroscopic parameters by the core--valence correlation, relativistic and nonadiabatic corrections have been discussed in detail. The core--valence correlation correction is carried out at the aug-cc-pCVTZ basis set. The nonadiabatic correction is performed at the aug-cc-pVTZ basis set. And the relativistic correction is made at the level of cc-pV5Z basis set. The way to consider the relativistic correction is to employ the second-order Douglas--Kroll Hamiltonian (DKH2) approximation. To obtain more reliable PECs, the Davidson modification is also included in the present study. To reduce the incomplete basis set error, the \{PECs\} of these electronic states are extrapolated to the complete basis set (CBS) limit. With these PECs, the spectroscopic parameters of these low-lying electronic states are determined. On the one hand, analyses demonstrate that the effects on the spectroscopic parameters by the core--valence correlation correction, relativistic correction and Davidson modification are very obvious, whereas the effect on the spectroscopic parameters by the nonadiabatic correction is very small. On the other hand, comparison with the \{RKR\} data shows that the two-point total-energy extrapolation could improve the quality of spectroscopic parameters. On the whole, as expected, the most accurate spectroscopic parameters of GeS molecule are determined by the MRCI+Q/CV+DK+Q5 calculations. },
	Author = {D. H. Shi and H. Liu and J. F. Sun and Z. L. Zhu and Y. F. Liu},
	Doi = {http://dx.doi.org/10.1016/j.jms.2011.06.001},
	Journal = JMS,
	Pages = {143 - 150},
	Title = {{Effects on spectroscopic parameters of several low-lying electronic states of GeS by core--valence correlation and relativistic corrections}},
	Volume = {269},
	Year = {2011}}

@article{14KaMixx.Re,
	Author = {Kaplan, I G and Miranda, Ulises},
	Journal = {Russian J. Phys. Chem. A},
	Pages = {1861--1871},
	Title = {{Multi-reference Ab initio calculations of 3d transition-metal dimers: Sc2}},
	Volume = {88},
	Year = {2014}}

@article{15ShLiWa.Re,
	Abstract = {The potential energy curves (PECs) of 59 Ω states generated from the 17 Λ-S states (X1Σ+, a3Σ +, 15Σ+, b3Δ, c 3Π, 15Π, 25Σ+, 2 3Δ, 23Π, 33Σ+, A 1Π, 23Σ+, 35Σ +, 17Σ+, 15Δ, 2 5Δ, and 25Π) of AsP molecule are studied for the first time for internuclear separations from about 0.10 to 1.10 nm. All the Λ-S states are contributed to the first three dissociation channels of AsP molecule except for the A1Π. The 23Σ +, 35Σ+, 17Σ +, 15Δ, 25Δ, and 25Π are found to be the repulsive states. The a3Σ+, 15Π, b3Δ, 17Σ+, 15Δ, 25Δ, and 25Π are found to be the inverted states. Each of the 33Σ+, c 3Π, 23Π, 15Π, and 1 5Σ+ states has one potential barrier. The PECs are calculated by the CASSCF method, which is followed by the internally contracted MRCI approach with Davidson correction. Core-valence correlation and scalar relativistic corrections are included. The convergent behavior of present calculations is discussed with respect to the basis set and level of theory. The spin-orbit coupling effect is accounted for. All these PECs are extrapolated to the complete basis set limit. The spectroscopic parameters are evaluated for the bound states involved, and are compared with available measurements. Excellent agreement has been found between the present results and the measurements. It shows that the spectroscopic parameters reported in this paper can be expected to be reliably predicted ones. The conclusion is gained that the effect of spin-orbit coupling on the spectroscopic parameters is not obvious for all the Λ-S bound states except for few ones such as 1 5Σ+ and c3Π. {\copyright} 2014 Elsevier B.V. All rights reserved.},
	Author = {Shi, D. and Liu, Q. and Wang, S. and Sun, J. and Zhu, Z.},
	Doi = {10.1016/j.saa.2014.07.065},
	Journal = SCAA,
	Pages = {736-746},
	Title = {{Accurate spectroscopic calculations of the 17 Λ-S and 59 Ω states of the AsP molecule including the spin-orbit coupling effect}},
	Volume = {135},
	Year = {2015}}

@article{89RaDaxx.Re,
	Abstract = {Ab initio multireference configuration-interaction (MRCI) calculations using localized molecular orbitals (LMO) were made to estimate adiabatic purely electronic transition energies of the six lowest excited states (a 3Σ+, A 3Π, B 1Σ+, C 1Π, E 1Δ) to the X 1Σ+ ground state of the CuF molecule. Spectroscopic constants for these states arefound to be in very good agreement with experimental data and are also reported. Results show again the very strong ionic character of the wavefunctions for all the studied states and that the excited states arise from the Cu+ 3D(d9s1) F− 1S(s2p6) and Cu+ 1D(d9s configurations. },
	Author = {A. Ram{\'\i}rez-Sol{\'\i}s and J. P. Daudey},
	Doi = {http://dx.doi.org/10.1016/0301-0104(89)80242-3},
	Journal = CP,
	Pages = {111 - 118},
	Title = {{Theoretical study of the spectroscopy of low-lying electronic states of the CuF molecule}},
	Volume = {134},
	Year = {1989}}

@article{96ChReSt.Re,
	Abstract = {MRCI(SD) calculations have been performed for the adiabatic potential curves and dipole transition moments of diatomic zinc. Only the four valence electrons of the system are treated explicitly, whereas the atomic cores are replaced by the energy-adjusted pseudopotentials. The spin-orbit coupling has not been considered. },
	Author = {E. Czuchaj and F. Rebentrost and H. Stoll and H. Preuss},
	Doi = {http://dx.doi.org/10.1016/0009-2614(96)00336-3},
	Journal = CPL,
	Pages = {203 - 209},
	Title = {{Potential energy curves for the Zn2 dimer}},
	Volume = {255},
	Year = {1996}}

@article{97CzReSt.Re,
	Abstract = {Potential energy curves for electronic states of the Hg2 dimer are calculated using the \{SCF\} and \{MRCI\} scheme for the four valence electrons of the system, with the core electrons represented by ab initio quasirelativistic energy adjusted pseudopotentials. Computations are performed for the molecular states that dissociate to the Hg(1S)+Hg(1S, 3P, 1P, 7s3S, 7s1S, 7p3P, 7p1P) asymptotes. The calculated potential curves are split into spin-orbit components in a semiempirical manner following the ``atoms-in-molecules'' model. Comparison of the derived potentials with known experimental data shows overall good agreement between theory and experiment, although the theoretical potentials are somewhat too shallow. },
	Author = {E. Czuchaj and F. Rebentrost and H. Stoll and H. Preuss},
	Doi = {http://dx.doi.org/10.1016/S0301-0104(96)00305-9},
	Journal = CP,
	Pages = {277 - 289},
	Title = {{Calculation of ground- and excited-state potential energy curves for the Hg2 molecule in a pseudopotential approach}},
	Volume = {214},
	Year = {1997}}

@article{97ShMaGi.Re,
	Abstract = {In the present work, all-electron ab initio multi-configuration self-consistent-field (CASSCF) and multi-reference configuration interaction (MRCI) calculations have been carried out to determine the low-lying electronic states of the molecule RhN. In addition, the relativistic corrections for the one-electron Darwin contact term and the relativistic mass-velocity correction have been determined in perturbation calculations. The spectroscopic constants for the seven low-lying electronic states have been derived by solving the Schr{\"o}dinger equation for the nuclear motion numerically. The predicted ground state of RhN is 1∑+, and this state is separated from the states 3Π, 1Π, 5Δ, 3∑−, 3Δ and 1Δ by transition energies of 1833, 4278, 6579, 8042, 9632, and 13886 cm−1, respectively. For the 1∑+ ground state, the equilibrium distance has been determined as 1.640 {\AA}, and the vibrational frequency as 846 cm−1. The chemical bond in the 1∑+ electronic ground state has triple bond character due to the formation of delocalized bonding π and σ orbitals. The chemical bond in the RhN molecule is polar with charge transfer from Rh to N giving rise to a dipole moment of 2.08 Debye at 3.1 a.u. in the 1∑+ ground state. An approximate treatment of the spin-orbit coupling effect shows that the lowest-lying spin-orbit coupled state is 0+. This state is essentially derived from the 1∑+ ground state. The second and third state, 0+ and 0−, mainly arise from the 3Π state. The dissociation energy of the RhN molecule in its 1∑+ ground state has been derived as 1.74 eV. },
	Author = {Irene Shim and Kim Mandix and Karl A. Gingerich},
	Doi = {http://dx.doi.org/10.1016/S0166-1280(96)04802-6},
	Journal = JMS,
	Pages = {127 - 139},
	Title = {Electronic states and nature of bonding in the molecule RhN by all-electron ab initio calculations},
	Volume = {393},
	Year = {1997}}

@article{99MaDaxx.Re,
	Abstract = {Ab initio based multireference singles and doubles configuration interaction (MRDCI) calculations are performed on the ground and low-lying electronic states of GaP using semi-core relativistic effective core potentials and spin-orbit operators. Potential energy curves of 39 Λ-S states which correlate with three lowest dissociation limits of GaP have been computed. Spectroscopic constants of 17 bound states upto the energy of 47 400 cm−1 are estimated. The ground state (X3Σ−) electronic configuration of GaP is found to be σ12σ22σ32π2 with re=2.5 {\AA} and ωe=268 cm−1. The best possible dissociation energy (De) of the ground state is calculated to be 39 kcals/mol which is smaller than the available experimental value by 15 kcals/mol. Effects of the spin-orbit coupling on the potential energy curves and spectroscopic constants of those electronic states which correlate with lowest two dissociation limits have been investigated. Spectroscopic properties of the spin-orbit states arising from lowest ten Λ-S states have been calculated. Electric dipole-allowed transitions like 3Π--X3Σ−, 33Π--3Π, 23Σ+--3Π, and 21Π--1Π are found to be more probable. Lifetimes of seven excited states: 41Σ+, 21Σ+, 21Π, 23Σ+, 3Σ+, 23Π, and 33Π are estimated. The 33Π and 23Σ+states are found to be short-lived with the radiative lifetimes lying between 0.01 and 0.2 μs. },
	Author = {Biswabrata Manna and Kalyan Kumar Das},
	Doi = {http://dx.doi.org/10.1016/S0166-1280(98)00485-0},
	Journal = JMS,
	Pages = {135 - 146},
	Title = {Multireference singles and doubles configuration interaction study on the electronic states of GaP},
	Volume = {467},
	Year = {1999}
}

@article{14BoGoCa.Re,
	Abstract = {The ground and low-lying electronic states of ReB were studied at the CASPT2//CASSCF level (multiconfigurational second-order perturbation theory) and quadruple-ζ ANO-RCC basis sets. Spectroscopic constants, potential energy curves, wavefunctions, and Mulliken population analysis are given. The ground state of ReB is of X 5 Σ + symmetry (R e  = 1.817 {\AA}, ω e  = .909 cm−1, and μ = 2.87 D), giving rise to a Ω = 0+ ground state after including spin-orbit coupling.},
	Author = {Borin, Antonio Carlos and Gobbo, Jo{\~a}oPaulo and Castro, C{\'e}sarAugustoMilani},
	Doi = {10.1007/s00894-014-2285-6},
	pages = {2285},
	Journal = {J. Molec. Modeling},
	Title = {The low-lying electronic states of ReB},
	Volume = {20},
	Year = {2014}}

@incollection{12LeShxx.Re,
	Abstract = {
The problem of calculation of the electronic structure of transition-metal clusters (even dimers) still presents a challenge for computational chemistry. The reason is that the expansion of the ground state wave function on electronic configurations does not contain a principal configuration and a large number of reference configurations must be treated equally. Thus the multireference (MR) approaches are, in general, mandatory.

According to our studies of Mn2 by the MRCISD(+Q)/aug-cc-pVQZ and ACPF approaches, the ground state is the singlet, X1Σ+g, with the binding energy D e = 1.7 kcal/mol (0.07 eV) and R e = 3.6 {\AA}. It was proved that the binding in the Mn2 dimer is of the van der Waals type. The calculation of Sc2 at the MRCISD(+Q)/cc-pV5Z level, showed that its ground state corresponds to a quintet, 5Σ−u, in agreement with experiment and previous precise calculations. The triplet 3Σ−u state is located about 1.1 kcal/mol above. The ground state, X5Σ−u, of the Sc2 dimer was calculated by the MRCISD(+Q) method at the complete basis set (CBS) limit. This is the first MRCISD(+Q) calculation of 3d transition-metal clusters at the CBS limit. From the Mulliken population analysis and comparison with atomic energies follows that in the ground state Sc2 dissociates on one Sc in the ground state and the other in the second excited quartet state, 4Fu. The spectroscopic parameters of the ground potential curve, obtained by the Dunham analysis at the valence MRCISD(+Q)/CBS level, are: R e = 5.20 bohr, D e = 50.37 kcal/mol, and ω e = 234.5 cm−1. The obtained value for the harmonic frequency agrees very well with the experimental one, ω e = 239.9 cm−1. The Sc2 dimer is stabilized by the covalent bonding on the hybrid atomic orbitals.
},
	Author = {Kaplan, IlyaG. and Miranda, Ulises},
	Booktitle = {Practical Aspects of Computational Chemistry II},
	Doi = {10.1007/978-94-007-0923-2_10},
	Editor = {Leszczynski, Jerzy and Shukla, Manoj K.},
	Pages = {361-389},
	Publisher = {Springer Netherlands},
	Title = {State-of-the-Art Calculations of the 3d Transition-Metal Dimers: Mn2 and Sc2},
	Year = {2012}}

@article{13SaMaxx.Re,
	Abstract = {We present a high level ab initio study of NiO and its ions, NiO+ and NiO−. Employing variational multireference configuration interaction (MRCI) and single reference coupled-cluster methods combined with basis sets of quintuple quality, 54, 20, and 10 bound states of NiO, NiO+, and NiO− have been studied. For all these states, complete potential energy curves have been constructed at the MRCI level of theory; in addition, for the ground states of the three species core subvalence (3s 23p 6/ Ni ) and scalar relativistic effects have been taken into account. We report energetics, spectroscopic parameters, dipole moments, and spin-orbit coupling constants. The agreement with experiment is in the case of NiO good, but certain discrepancies that need further investigation have arisen in the case of the anion whose ground state remains computationally a tantalizing matter. The cation is experimentally almost entirely unexplored, therefore, the study of many states shall prove valuable to further investigators. The ground state symmetry, bond distances, and binding energies of NiO and NiO+ are (existing experimental values in parenthesis), X 3Σ−(X 3Σ−), re = 1.606 (1.62712) {\AA}, D0 = 88.5 (89.2 $\pm$ 0.7) kcal/mol, and X 4Σ−(?), re = 1.60(?) {\AA}, D0 = 55 (62.4 $\pm$ 2.4) kcal/mol, respectively. The ground state of NiO− is 4Σ− (but 2Π experimentally) with D0 = 85--87 (89.2 $\pm$ 0.7) kcal/mol.},
	Author = {Sakellaris, Constantine N. and Mavridis, Aristides},
	Doi = {http://dx.doi.org/10.1063/1.4789416},
	Journal = JCP,
	Pages = {054308},
	Title = {{First principles exploration of NiO and its ions NiO+ and NiO−}},
	Volume = {138},
	Year = {2013}}

@article{14CoMuxx.Re,
	Abstract = {Abstract We calculate potential curves for transition metal dimers using Monte Carlo configuration interaction (MCCI). These results, and their associated spectroscopic values, are compared with experimental and computational studies. The multireference nature of the \{MCCI\} wavefunction is quantified and we estimate the important orbitals. We initially consider the ground state of the chromium dimer. Next we calculate potential curves for Sc2 where we contrast the lowest triplet and quintet states. We look at the molybdenum dimer where we compare non-relativistic results with the partial inclusion of relativistic effects via effective core potentials, and report results for scandium nickel. },
	Author = {J. P. Coe and P. Murphy and M. J. Paterson},
	Doi = {http://dx.doi.org/10.1016/j.cplett.2014.04.050},
	Journal = CPL,
	Pages = {46 - 52},
	Title = {{Applying Monte Carlo configuration interaction to transition metal dimers: Exploring the balance between static and dynamic correlation}},
	Volume = {604},
	Year = {2014}}

@article{12SaMaxx.Re,
	Abstract = { We present a systematic and high-level ab initio study of CoO and its ions, CoO+ and CoO--. Employing variational multireference (MRCI) and single-reference coupled--cluster methods combined with basis sets of quintuple quality, we have calculated 50, 31, and 7 bound states for CoO, CoO+, and CoO--, respectively. For all these states, complete potential energy curves have been constructed at the MRCI level of theory, whereas for a few low-lying states core subvalence and scalar relativistic effects have been taken into account. We report energetics, spectroscopic parameters, dipole moments, and spin--orbit coupling constants. The ground states of CoO, CoO+, and CoO-- are X4Δ, X5Δ, and X5Δ, respectively, the latter established for the first time. The CoO is quite ionic with a Co to O Mulliken charge transfer of ∼0.6 electrons and a dipole moment μ(X4Δ) = 4.5 $\pm$ 0.1 D. The overall agreement between theory and experiment is good, but there are also important deviations. Despite the seeming simplicity of these diatomic species, reliable results can only be obtained at a high level of theory. },
	Author = {Sakellaris, Constantine N. and Mavridis, Aristides},
	Doi = {10.1021/jp303906s},
	Journal = JPCA,
	Pages = {6935-6949},
	Title = {{Electronic Structure and Bonding of Cobalt Monoxide, CoO, and Its Ions CoO+ and CoO--: An Ab Initio Study}},
	Volume = {116},
	Year = {2012}}

@article{06TzMaxx.Re,
	Abstract = { The ground and 18 low lying excited states of the diatomic molecule cobalt carbide, CoC, have been examined by multireference variational methods (MRCI) combined with quantitative basis sets. All calculated states are bound and correlate adiabatically to the ground-state atoms, Co(a4F) + C(3P). We report complete potential energy curves, equilibrium bond distances, dissociation energies (De), spectroscopic constants, electric dipole moments and spin−orbit splittings. The bonding character of certain states is also discussed with the help of Mulliken distributions and valence-bond-Lewis diagrams. We are practically certain that the ground state is of 2Σ+ symmetry with a state of 2Δ symmetry lying less than 3 kcal/mol higher, in agreement with the relevant experimental findings. Our best estimate of the X 2Σ+ dissociation energy is De(D0) = 83(82) kcal/mol at re = 1.541 {\AA}, 0.02 {\AA} shorter than the experimental bond length. },
	Author = {Tzeli, Demeter and Mavridis, Aristides},
	Doi = {10.1021/jp062357g},
	Journal = JPCA,
	Pages = {8952-8962},
	Title = {{Electronic Structure of Cobalt Carbide, CoC}},
	Volume = {110},
	Year = {2006}}

@article{11GoMaxx.Re,
	Abstract = {The computational description of the catalytic processes on the surface of transition metals (TMs) requires methods capable of accurate prediction of the bond forming and breaking between the atoms of metal and other elements. In our previous report [Goel and Masunov, J Chem Phys, 129, 214302, 2008], we studied TM hydrides and found that Boese--Martin functional for kinetics (BMK) combined with broken symmetry approach described dissociation process more accurately than multireference wavefunction theory (WFT) methods and some other functionals. Here, we investigate the binding energy, geometry, electronic structure, and potential energy curves for diatomic TM carbides using several exchange-correlation functionals. The functionals that include explicit dependence on the kinetic energy density (τ-functionals) are considered, among others. We have found M05-2x performance to be the best, followed by BMK, when compared with experimental and high level WFT energetics. This agreement deteriorates quickly for other functionals when the fraction of the Hartree--Fock exchange is decreased. Scalar relativistic corrections yield mixed results for bond lengths and bond energies. The natural bond orbital analysis provides useful insight in description of stable spin state over others in these diatomics. {\copyright} 2011 Wiley Periodicals, Inc. Int J Quantum Chem, 2011},
	Author = {Goel, Satyender and Masunov, Art{\"e}m E.},
	Doi = {10.1002/qua.22950},
	Issn = {1097-461X},
	Journal = IJQC,
	Pages = {4276--4287},
	Title = {{Dissociation curves and binding energies of diatomic transition metal carbides from density functional theory}},
	Volume = {111},
	Year = {2011}}

@article{15Kaxxxx.Re,
	Abstract = {We have studied 175 molecular states of the Fe2 diatomic by constructing full potential energy curves dissociating to the ground Fe(5D) + Fe(5D) and first excited Fe(5D) + Fe(5F) dissociation channels by multireference configuration interaction methods and large basis sets. The ground X9Σ−g and the first excited 7Σ−u states have been detailed by a multitude of plain and explicitly correlated F12 methods at both the valence and core-valence computational levels. The potential curves of most of the states present strong interactions/avoided crossings that trigger a severe non adiabatic behavior. For reasons of completeness, the ground states of the charged Fe−,+2 species have also been considered.},
	Author = {Kalemos, Apostolos},
	Doi = {http://dx.doi.org/10.1063/1.4922793},
	Journal = JCP,
	Pages = {244304},
	Title = {{Fe2: As simple as a Herculean labour. Neutral (Fe2), cationic (Fe2+), and anionic (Fe2−) species}},
	Volume = {142},
	Year = {2015}}

@article{12KrMoKa.Re,
	Abstract = {Diatomic TiFe, a 12 valence electron molecule that is isoelectronic with Cr2, has been spectroscopically investigated for the first time. In addition, the first computational study that includes the ground and excited electronic states is reported. Like Cr2, TiFe has a 1Σ+ground state that is dominated by the 1σ2 2σ2 1π4 1δ4 configuration. Rotationally resolved spectroscopy has established a ground statebond length of 1.7024(3) {\AA}, quite similar to that found for Cr2 (r0 = 1.6858 {\AA}). Evidently, TiFe exhibits a high degree of multiple bonding. The vibronic spectrum is highly congested and intense to the blue of 20 000 cm−1, while two extremely weak band systems, the [15.9]3Π1 ← X 1Σ+ and [16.2]3Π0+ ← X 1Σ+ systems, are found in the 16 000--18 500 cm−1 region. The bond lengths, obtained by inversion of the Be ′ values, and vibrational frequencies of the two upper states are nearly identical: 1.886 {\AA} and 344 cm−1 for [15.9]3Π1 and 1.884 {\AA} and 349 cm−1 for [16.2]3Π0+ . The measured spin-orbit splitting of the 3Π state is consistent with its assignment to the 1σ2 2σ2 1π4 1δ3 2π1 configuration, as is also found in the ab initio calculations.},
	Author = {Krechkivska, Olha and Morse, Michael D and Kalemos, Apostolos and Mavridis, Aristides},
	Journal = JCP,
	Pages = {054302},
	Title = {{Electronic spectroscopy and electronic structure of diatomic TiFe}},
	Volume = {137},
	Year = {2012}}

@article{01TzMaxx.Re,
	Abstract = { Using ab initio multireference methods and large correlation consistent basis sets, we have investigated the ground electronic structure of the carbides BC and AlC, the ground and the first two excited states of the corresponding anions, BC- and AlC-, and the ground (linear) structures of the hydrides H−BC and H−AlC. By employing a series of increasing size basis sets for the BC molecule, i.e., cc-pVnZ, aug-cc-pVnZ, cc-pCVnZ, and aug-cc-pCVnZ, n = 2, 3, 4, and 5, we have examined the convergence of its properties as a function of n. For both the neutral diatomic species and their anions we have obtained full potential energy curves, bond distances (re), dissociation energies (De), and the usual spectroscopic constants. For the BC molecule, our best re and De values are re = 1.4911 {\AA} and De = 102.2 kcal/mol in excellent agreement with experimental results. In the AlC case the calculated De = 77.13 kcal/mol is at least 12 kcal/mol higher than the experimental number. No experimental or theoretical data exist in the literature for the anion BC-. For this system we obtain re = 1.4445 {\AA} and De = 118.67 kcal/mol; the corresponding values of the AlC- species are re = 1.8945 {\AA} and De = 77.16 kcal/mol. },
	Author = {Tzeli, Demeter and Mavridis, Aristides},
	Doi = {10.1021/jp003258k},
	Journal = JPCA,
	Pages = {1175-1184},
	Title = {{First-Principles Investigation of the Boron and Aluminum Carbides BC and AlC and Their Anions BC- and AlC-. 1}},
	Volume = {105},
	Year = {2001}}

@article{02KePiCa.Re,
	Abstract = {We test the recently developed state-specific multireference Brillouin-Wigner coupled cluster (MRBWCCSD) method against the single reference CCSD method by examining theoretically the competing X3Σ- and 5Σ- states of the (experimentally unknown) isovalent calcium and zinc carbide diatomics (CaC, ZnC). At the CCSD level, CaC is "incorrectly" predicted to have a ground 5Σ- state; however, the MRBWCCSD treatment restores the correct state ordering, and improves significantly the energetics for both molecules. Further comparison with various single- and multireference treatments shows that the latter are absolutely necessary for obtaining meaningful results for the ground states in both molecules.},
	Author = {Kerkines, Loannis SK and Pittner, Jir{\'\i} and C{\'a}rsky, Petr and Mavridis, Aristides and Hubac, Ivan},
	Journal = JCP,
	Pages = {9733--9739},
	Title = {{On the ground states of CaC and ZnC: A multireference Brillouin-Wigner coupled cluster study}},
	Volume = {117},
	Year = {2002}}

@article{01KaMaHa.Re,
	Abstract = { The electronic structure of the diatomic carbide ScC has been investigated by ab initio multireference methods in conjunction with large basis sets. The ground state has been determined to be of 2Π symmetry with De = 65.5 kcal/mol and Re = 1.988 {\AA}. Eight more states have been examined within an energy range of about 1 eV, with the first excited state (4Π) being 1.2 kcal/mol higher. },
	Author = {Kalemos, Apostolos and Mavridis, Aristides and Harrison, James F.},
	Doi = {10.1021/jp003031p},
	Journal = JPCA,
	Pages = {755-759},
	Title = {{Theoretical Investigation of Scandium Carbide, ScC}},
	Volume = {105},
	Year = {2001}}

@article{02TzMaxx.Re,
	Author = {Tzeli, Demeter and Mavridis, Aristides},
	Journal = JCP,
	Pages = {4901},
	Title = {Theoretical investigation of iron carbide, FeC},
	Volume = {116},
	Year = {2002}}

@article{11Kaxxxx.Re,
	Abstract = {The Ti2 and Ti2 + molecular systems have been studied through multireference variational and single reference coupled-cluster methods coupled with large basis sets. Potential energy curves have been constructed for 30 (Ti2) and 2 (Ti2 +) states and the usual spectroscopic parameters have been extracted. The main feature of the potential curves is the existence of van der Waals minima (Ti2) around 7 bohr irrespective of the molecular symmetry, and 4s 2--4s 1 interactions (Ti2 +) around 6 bohr. Numerous avoided crossings lead to stronger covalent bonds emanating from 4s 1--4s 1 atomic distributions. The X-state of the neutral species is formally a 3Δg state with the first excited state lying within 1 kcal/mol. The removal of the symmetry defining e− leads to the X2Σg + state of Ti2 +.},
	Author = {Kalemos, Apostolos and Mavridis, Aristides},
	Doi = {http://dx.doi.org/10.1063/1.3643380},
	Journal = JCP,
	Pages = {134302},
	Title = {{The electronic structure of Ti2 and Ti2+}},
	Volume = {135},
	Year = {2011}}

@article{12SaMaxx2.Re,
	Abstract = {The electronic structure of the diatomic species CoH, CoH+, and CoH− have been studied mainly by multireference configuration interaction (MRCI) methods and basis sets of quintuple quality. The restricted coupled-cluster with iterative singles + doubles + quasi-perturbative connected triples, RCCSD(T), approach was also employed, limited however to the ground states only. At the MRCI level we have constructed 27 (CoH), 24 (CoH+), and 12 (CoH−) potential energy curves correlating adiabatically to six, seven, and two energy channels, respectively. For the ground states scalar relativistic and core--subvalence effects have been taken into account. We report energetics, spectroscopic parameters, dipole moments, excitation energies, and spin--orbit coupling constants. Our CoH calculated results are in accord with experiment, but there is an interesting discrepancy between theory and experiment concerning the dipole moment, the former being significantly larger than the latter. Experimental results on CoH+ and CoH− are scarce. The ground state of CoH, CoH+, and CoH− are definitely of 3Φ, 4Φ, and 4Φ symmetries with calculated (experimental) dissociation energiesD00 = 46.4 $\pm$ 0.5(45.0 $\pm$ 1.2), 49.6(47 $\pm$ 2), and 45.6(43.1 $\pm$ 1.2) kcal/mol, respectively. In all 24 calculated CoH states, a Co--to--H charge transfer of 0.2--0.3 e− is recorded; in CoH−, however, the negative charge resides almost exclusively on the Co atom.

},
	Author = {Sakellaris, Constantine N. and Mavridis, Aristides},
	Doi = {http://dx.doi.org/10.1063/1.4734595},
	Journal = JCP,
	Pages = {034309},
	Title = {{First principles study of cobalt hydride, CoH, and its ions CoH+ and CoH−}},
	Volume = {137},
	Year = {2012}}

@incollection{15Duxxxx.Re,
	Author = {Kalemos, Apostolos and Mavridis, Aristides},
	Booktitle = {Thom H. Dunning, Jr.},
	Doi = {10.1007/978-3-662-47051-0_20},
	Editor = {Wilson, Angela K. and Peterson, Kirk A. and Woon, David E.},
	Isbn = {978-3-662-47050-3},
	Pages = {223-231},
	Publisher = {Springer Berlin Heidelberg},
	Series = {Highlights in Theoretical Chemistry},
	Title = {All electron ab initio calculations on the ScTi molecule: a really hard nut to crack},
	Volume = {10},
	Year = {2015}}

@article{09KaMaxx.Re,
	Abstract = { The titled molecular species have been studied by ab initio multireference and coupled-cluster methods in conjunction with large correlation consistent basis sets. A total of 71 MCl, 13 MCl+, and 9 MCl− states, M = Sc, Ti, V, Cr, have been examined. We report total energies, dissocation energies, spectroscopic parameters, and full potential energy curves. Most of our results are presented for the first time in the literature, whereas the general agreement with available experimental data can be considered as quite good. },
	Author = {Kardahakis, Stavros and Mavridis, Aristides},
	Doi = {10.1021/jp901225y},
	Journal = JPCA,
	Pages = {6818-6840},
	Title = {First-Principles Investigation of the Early 3d Transition Metal Diatomic Chlorides and Their Ions, ScCl0,$\pm$, TiCl0,$\pm$, VCl0,$\pm$, and CrCl0,$\pm$},
	Volume = {113},
	Year = {2009}}

@article{12DeAlxx.Re,
	Abstract = {The low-lying electronic states (X  4Δ, A  4Π, a  6Δ, b  6Π) of the iron monohydride radical, which are especially troublesome for electronic structure theory, have been successfully described using a focal point analysis (FPA) approach that conjoined a correlation-consistent family of basis sets up to aug-cc-pwCV5Z-DK with high-order coupled cluster theory through hextuple (CCSDTQPH) excitations. Adiabatic excitation energies (T 0) and spectroscopic constants (r e, r 0, B e, B 0, D⎯⎯⎯ e, ω e, v 0, α e, ω e x e) were extrapolated to the valence complete basis set Douglas-Kroll (DK) aug-cc-pwCV∞Z-DK CCSDT level of theory, and additional treatments accounted for higher-order valence electron correlation, core correlation, spin-orbit coupling, and the diagonal Born-Oppenheimer correction. The purely ab initio FPA approach yields the following T 0 results (in eV) for the lowest spin-orbit components of each electronic state: 0 (X  4Δ) < 0.132 (A  4Π) < 0.190 (a  6Δ) < 0.444 (b  6Π). The computed anharmonic fundamental vibrational frequencies (v 0) for the 4,6Δ electronic states are within 3 cm−1 of experiment and provide reliable predictions for the 4,6Π states. With the cc-pVDZ basis set, even CCSDTQPH energies give an incorrect ground state of FeH, highlighting the importance of combining high-order electron correlation treatments with robust basis sets when studying transition-metal radicals. The FPA computations provide D 0 = 1.86 eV (42.9 kcal mol−1) for the 0 K dissociation energy of FeH and ΔfH∘298 [FeH(g)] = 107.7 kcal mol−1 for the enthalpy of formation at room temperature. Despite sizable multireference character in the quartet states, high-order single-reference coupled cluster computations improve the spectroscopic parameters over previous multireference theoretical studies; for example, the X  4Δ → A  4Π and a  6Δ → b  6Π transition energies are reproduced to 0.012 and 0.002 eV, respectively, while the error for the problematic X  4Δ → a  6Δ intercombination excitation is reduced from at least 0.17 eV to about 0.04 eV.},
	Author = {DeYonker, Nathan J. and Allen, Wesley D.},
	Doi = {http://dx.doi.org/10.1063/1.4767771},
	Journal = JCP,
	Pages = {234303},
	Title = {{Taming the low-lying electronic states of FeH}},
	Volume = {137},
	Year = {2012}}

@article{14DeHaAl.Re,
	Abstract = {Six electronic states (X 4Σ−, A 4Π, B 4Δ, 2Φ, 2Δ, 2Σ+) of the vanadium monochloride cation (VCl+) are described using large basis set coupled cluster theory. For the two lowest quartet states (X 4Σ− and A 4Π), a focal point analysis (FPA) approach was used that conjoined a correlation-consistent family of basis sets up to aug-cc-pwCV5Z-DK with high-order coupled cluster theory through pentuple (CCSDTQP) excitations. FPA adiabatic excitation energies (T 0) and spectroscopic constants (r e, r 0, B e, B 0, D⎯⎯⎯ e, H e, ω e, v 0, α e, ω e x e) were extrapolated to the valence complete basis set Douglas-Kroll (DK) aug-cc-pV∞Z-DK CCSDT level of theory, and additional treatments accounted for higher-order valence electron correlation, core correlation, and spin-orbit coupling. Due to the delicate interplay between dynamical and static electronic correlation, single reference coupled cluster theory is able to provide the correct ground electronic state (X 4Σ−), while multireference configuration interaction theory cannot. Perturbations from the first- and second-order spin orbit coupling of low-lying states with quartet spin multiplicity reveal an immensely complex rotational spectrum relative to the isovalent species VO, VS, and TiCl. Computational data on the doublet manifold suggest that the lowest-lying doublet state (2Γ) has a T e of ∼11 200 cm−1. Overall, this study shows that laboratory and theoretical rotational spectroscopists must work more closely in tandem to better understand the bonding and structure of molecules containing transition metals.},
	Author = {DeYonker, Nathan J and Halfen, DeWayne T and Allen, Wesley D and Ziurys, Lucy M},
	Journal = JCP,
	Pages = {204302},
	Title = {{The electronic structure of vanadium monochloride cation (VCl+): Tackling the complexities of transition metal species}},
	Volume = {141},
	Year = {2014}}