1.3.6 New Features in Q-Chem 5.1

Improved OpenMP parallelization for:

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  SCF vibrational frequency calculations (Zhengting Gan)

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  RIMP2 gradient (Fazle Rob, Joonho Lee, Xintian Feng, Evgeny Epifanovsky)

Complete active space self-consistent field (CASSCF) and adaptive sampling CI (Daniel Levine, Martin Head-Gordon)

Tkatchenko-Scheffler van der Waals method (Section 5.7.5) and many-body dispersion method (Section 5.7.6) (Denis Barton, Ka Un Lao, & Rob DiStasio)

Enhancements to the coupled-cluster package:

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  Core/valence separation for EOM-CCSD core-level excited and ionized states (Marta Vidal, Anna Krylov, Xintian Feng, Evgeny Epifanovsky, Sonia Coriani), Section 7.10.8.

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  NTO analysis of two-photon transitions (Kaushik Nanda, Anna Krylov), Section 7.10.20.6.

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  NTO analysis of the complex-valued EOM wave functions (Anna Krylov, Wojciech Skomorowski), Section 7.10.20.

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  Analytic gradients for Cholesky-decomposed and resolution-of-identity CCSD and EOM-CCSD (Xintian Feng, Anna Krylov).

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  Improved performance, reduced disk usage by coupled-cluster methods (Evgeny Epifanovsky, Ilya Kaliman, Xintian Feng).

New features in NTO analysis: Energies of NTOs (Anna Krylov), Section 10.2.9.

Finite-difference evaluation of non-linear properties (Marc de Wergifosse, Anna Krylov), Section 10.13.3.

Poisson boundary conditions for SCF calculations (Marc Coons, John Herbert), Section 11.2.11.

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  Enables quantum chemistry calculations in an arbitrary (anisotropic and inhomogeneous) dielectric environment.

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  Nonequilibrium solvent corrections for vertical ionization energies.

Energy decomposition analysis (EDA):

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  EDA based on symmetry-adapted perturbation theory and constrained DFT (SAPT/cDFT-EDA), Section 12.15 (Ka Un Lao, Kevin Carter-Fenk, John Herbert)

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  ALMO-EDA for CIS and TDDFT/TDA excited states, Section 12.11 (Qinghui Ge, Yuezhi Mao, Martin Head-Gordon)

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  Perturbative ALMO-CTA and COVP analysis in EDA2 (Yuezhi Mao, Martin Head-Gordon)

Analytic derivative couplings for computing excitation/vibration energy couplings within the ab initio Frenkel-Davydov exciton model (Adrian Morrison, John Herbert), Section 12.17.

Hyperfine and nuclear quadrupole couplings, Section 10.12.4 (Eric Berquist, Daniel Lambrecht)

Variational two-electron reduced-density-matrix (v2RDM) and v2RDM-driven complete active space self-consistent field (v2RDM-CASSCF) method (Gergely Gidofalvi, Lauren Koulias, Wayne Mullinax, Eugene DePrince)

Frozen and restrained potential energy scans, Section 9.7 (Yihan Shao)

Extended ESP charge fitting procedure to the computation of RESP charges (Yihan Shao)