1.3 Q-Chem Features

1.3.1 New Features in Q-Chem 5.3

  • Changes in default settings:

    • Renamed rem variable ADIABATIC_CTA to VFB_CTA

    • Changed ROHF_DIAG_SPEC default from 0 to 2 for ROHF and set GEN_SCFMAN as default ROSCF engine

  • General improvements:

    • Added support for the jun-cc-pVDZ basis set (K. Carter-Fenk)

  • New features and improvements in the DFT suite:

    • TD-DFT analytic force and frequencies for meta-GGA density functionals

    • Level shifting in DIIS for better SCF convergence in difficult cases (Section 4.5)

    • M06-SX density functional (P. Morgante, R. Peverati)

    • HF-3c method (B. Rana, J. Herbert)

  • New features and improvements in the CC/EOM-CC package:

    • Calculation of RIXS and orbital analysis of RIXS transition moments (K. Nanda, A.I. Krylov; Section 7.9.6.1)

    • New features in the CVS-EOM-CC suite (M. Vidal, S. Coriani)

    • Energies and properties for EOM-DEA-CCSD (S. Gulania, M. Ivanov, A.I. Krylov; Section 7.9.5)

    • Transition properties and <S2> for EOM-DIP-CCSD (S. Gulania, W. Skomorowski, A.I. Krylov)

    • New NLO properties (hyperpolarizabilities) in EOM-CC (K. Nanda, A.I. Krylov)

    • New tools for strongly correlated and magnetic systems: Extention of FNO to open-shell references (P. Pokhilko, A.I. Krylov; Section 7.9.9)

    • Construction of effective Hamiltonians from EOM-CC wavefunctions (P. Pokhilko, A.I. Krylov; Section 13.5)

    • NTO analysis of spin-forbidden transitions (P. Pokhilko, A.I. Krylov; Section 7.9.18.2)

    • Search for special points of complex PES (minima, MECP, and exceptional points) within CAP-EOM-CCSD (Z. Benda, T.-C. Jagau)

    • Voronoi CAP and projected CAP methods (J. Gayvert, K. Bravaya; Section 7.9.7)

    • New tools for computing Auger decay rates and resonance lifetimes by the Feshbach-Dyson method (W. Skomorowski, A.I. Krylov)

    • Stability improvements in EOM-CC (P. Pokhilko, A.I. Krylov)

  • New features and improvements in MP2 methods:

    • Geometry optimization with regularized orbital-optimized second-order Møller-Plesset perturbation theory (κ-OOMP2) (Joonho Lee, M. Head-Gordon; Section 6.6.5)

  • New capabilities for intermolecular interactions:

    • Implementation of the XSAPT+MBD method (K. Carter-Fenk, J. Herbert)

  • QM/MM improvements:

    • L-BFGS algorithm for geometry optimization (B. Rana and J. Herbert)

    • Harmonic confining potentials (S. Dasgupta and J. Herbert)

  • New methods and capabilities:

    • Nuclear-electronic orbital DFT and TD-DFT methods (F. Pavosevic, Zhen Tao, S. Hammes-Schiffer)

    • New module for RAS-SF methods (S. Houck, N. Mayhall)

    • A family of configuration-interaction methods: non-orthogonal configuration interaction singles (NOCIS), static exchange (STEX), and one-center NOCIS (K. Oosterbaan, M. Head-Gordon)

    • Integral screening and resolution-of-the-identity capabilities for complex basis functions (T.-C. Jagau)

    • RI-MP2 method for complex basis functions (M. Hernández Vera, T.-C. Jagau; Section 6.6.8)

    • New method (concentric localization) for truncating the virtual space in projector-based embedding theory (Yuezhi Mao)

    • Square gradient minimization for excited-state orbital optimization (D. Hait, M. Head-Gordon)

    • Resonance Raman spectroscopy simulation (S. Dasgupta, B. Rana, J. Herbert)

    • Population analysis of antibonding orbitals (A. Aldossary)

    • Fragment-based diabatization schemes (Yuezhi Mao)

    • Enabled ghost atoms without basis functions (B. Alam and J. Herbert)

    • Electron localization function (A. Bushra, J. Herbert)

    • New input options for wavefunction analysis (F. Plasser)

  • New features in the BrianQC GPU module:

    • Extended support for GPU accelerated DFT exchange-correlation with support for LDA, GGA, and meta-GGA functionals

    • Partially GPU accelerated DFT frequency calculations