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1.3 Q-Chem Features

1.3.2 New Features in Q-Chem 6.2

(May 7, 2024) Features in 6.2.0

  • Changes to default behavior:

    • Set POINT_GROUP_SYMMETRY to FALSE for freq jobs reading guess from previous job to avoid reorientation

    • Make NO_REORIENT = 1 and POINT_GROUP_SYMMETRY = 0 the defaults for harmonic confiner jobs

    • Make improved initial guess Hessian the default for optimizations (INITIAL_HESSIAN = MODEL)

    • Enable RI-K virtual orbital correction by default for occ-RI-K frequency jobs

  • General features and improvements:

    • NEO Multistate DFT (NEO-MSDFT) (Joseph Dickinson, Qi Yu, Sharon Hammes-Schiffer)

    • Added simulation of nuclear-electronic quantum dynamics based on real-time nuclear-electronic orbital (RT-NEO) (Tao E. Li, Mathew Chow, Sharon Hammes-Schiffer)

    • Added support for D3 empirical dispersion correction (energies and gradients) and Effective Core Potential (ECP) (energies and gradients) for NEO approach and RT-NEO methods (Mathew Chow, Sharon Hammes-Schiffer)

    • Constrained NEO (CNEO) for a single NEO center (Eno Paenurk, Sharon Hammes-Schiffer)

    • Addition of SCS-RIMP2 and SOS-OOMP2 to NEO methods (Jonathan Fetherolf, Sharon Hammes-Schiffer)

    • Faster NEO-SCF via simultaneous DIIS optimization (Mathew Chow, Sharon Hammes-Schiffer)

    • Add atomic multipole moment calculation using IAOs (Alexandra McIsaac, Abdulrahman Aldossary, Martin Head-Gordon)

    • Update the list of occasions not allowed for the AUTOSAD -> CORE fallback when atomic jobs fail (Yuezhi Mao)

    • New syntax allowing external electric field to follow a bond (Tarek Scheele, Tim Neudecker)

    • Real-time extension of TAO-DFT (RT-TAO) (Hung-Yi Tsai, Jeng-Da Chai)

    • SCF energy prints now break one-electron terms into kinetic, nuclear attraction and remainder when SCF_FINAL_PRINT is set to TRUE

    • Resolved issues with:

      • *

        Incorrect hydrogen isotope mass when using EPC functionals with NEO (Mathew Chow, Zhen (Coraline) Tao, Sharon Hammes-Schiffer)

      • *

        NEO Hessian implementation for range-separated functionals (Eno Paenurk and Sharon Hammes-Schiffer)

      • *

        Failure of the READ_REAL guess of complex RHF (Yuezhi Mao)

      • *

        Libopt3 misclassification of structure type for near-zero eigenvalues

      • *

        “SVD Failed" invalid step error in rare geometry optimization cases

  • Density functional theory and self-consistent field:

    • Implemented DFT/CIS, including a new parameterization for X-ray spectroscopy (Aniket Mandal, John Herbert)

    • Addition of new TZVP basis set for DFT/CIS to QCAUX (Aniket Mandal, John Herbert)

    • Implemented suppression of open-shell mixing for ROKS calculations (Juanes Arias-Martinez, Martin Head-Gordon)

    • Enable negative s8 values for Grimme’s D4 dispersion correction

    • Dipole filtering for restricted and unrestricted TDKS (John Herbert, Avik Kumar Ojha)

    • Print spatial overlaps of orbitals (intermediate overlaps for occ/virt pairs) (John Herbert)

    • Make virtual orbital correction after SCF convergence optional for occ-RI-K

    • Enable MakeMeSAD for GEN_SCFMAN

    • Add SAD guesses for cc-pV6Z and aug-cc-pV6Z

    • Disable AUTOSAD guess for CDFT-CI (John Herbert)

    • Disable NTOs for RPA (John Herbert)

    • Resolved issues with:

      • *

        Job control through FDIFF_DER for anharmonic frequency calculations (Yuezhi Mao)

      • *

        Anharmonic frequency calculation failure with DFT (Yuezhi Mao)

      • *

        Restart initialization for unrestricted TDKS (Hung-Yi Tsai, Jeng-Da Chai)

      • *

        Bug in RI related to basis sets that use multishells (note that this does not affect most RI calculations, unless an auxiliary multishell basis is used)

  • Correlated methods:

    • Added hyperfine coupling code to calculate couplings between singlet/triplet excited CIS states (Samuel May, Joseph Subotnik)

    • Generalization of 1C-NOCIS to two-electron open-shell singlets (Juanes Arias-Martinez, Hamlin Wu, Martin Head-Gordon)

    • Implemented the ACP-EOMIP-CCSD method to compute partial Auger decay widths (Florian Matz, Thomas Jagau)

    • Built-in implementation of calculations of x-secs and pads using Dyson orbitals (Madhubani Mukherjee, Sarai Folkestad, Anna Krylov)

    • Natural Auger Orbitals for Auger decay, ICD, and related processes for CVS-EOM methods (Nayanthara K. Jayadev, Anna I. Krylov)

    • Added BW-s2 method (Kevin Carter-Fenk, Martin Head-Gordon)

    • Stochastic resolution of identity to CC2 (sRI-CC2) for excited state energy calculations (Chongxiao Zhao, Wenjie Dou, Joonho Lee)

    • EOM-CCSDT for EE and SF states (Manisha, Prashant Uday Manohar)

    • Resolved issues with:

      • *

        Legacy RI-MP2 code crashes when MEM_STATIC value is too large (Yuezhi Mao)

      • *

        Error in calculation of the separable part of the one-particle density matrix with CCSD (Yongbin Kim, Madhubani Mukherjee, Anna Krylov)

      • *

        Overwriting of Molden files for natural Auger orbitals in resonant Auger decay calculations (Nayanthara Karippara Jayadev, Anna Krylov)

  • Molecular dynamics, non-adiabatic dynamics, embedding, and solvation improvements:

    • External/embedded potential read (Huseyin Aksu, Barry Dunietz)

    • Turn on PCM at the first SCF iteration when SCF_GUESS = READ, allowing faster convergence (Yuezhi Mao)

    • Turn on PCM at the first SCF iteration in the 2nd geom opt cycle for FRAGMO and AUTOSAD (Yuezhi Mao)

    • Clarified ambiguous output for COSMO (John Herbert)

    • Added analytic X-HCFF Hessian (Rahel Weiss, Felix Zeller, Tim Neudecker)

    • Resolved issues with:

      • *

        Out-of-bound access error for SMX with ghost atoms

      • *

        Undesirable behavior of SOLVENT_METHOD = TRUE invoking Kirkwood model (John Herbert)

      • *

        Add missing qarchive files for QM/MM calculations (Xiaoliang Pan, Yihan Shao)

      • *

        Incorrectly increasing van der Waals radii for I and At atoms in jobs with multiple SMD calculations (Zheng Pei)

  • Fragment and energy decomposition analysis improvements:

    • Add additional printout for libwfa regarding ionic/covalent states (Felix Plasser)

    • Resolved issues with:

      • *

        Occasional crash in non-perturbative CTA (Yuezhi Mao)

  • Post-processing features:

    • Calculations of g-tensors using ezMagnet (Sven Kähler, Antonio Cebreiro-Gallardo, Pavel Pokhilko, David Casanova, and Anna I. Krylov)