1.3.4 New Features in Q-Chem 5.2

Changes in default settings:

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  Single-node shared-memory parallelism becomes default and recommended for most jobs. New command line key -mpi is required to use distributed-memory MPI-parallel features (Section 2.8).

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  Pure basis functions are used by default with BASIS = GEN.

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  Default number of grid points in Lebedev grids in solvent models changed from 302 to 194 points (non-Hydrogen) and 110 points (Hydrogen) atoms.

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  Use of SWIG charges for SMx models.

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  Input format for XPol, SAPT and XSAPT, and MBE jobs has changed.

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  Use EDA2 as the default driver for ALMO-EDA.

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  Frozen core approximation no longer applied by default in RAS-CI calculations.

General improvements:

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  Increased availability of basis sets: High angular momentum basis functions (up to k-functions) supported for most SCF, RI-MP2, CC, EOM-CC, ADC calculations.

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  Streamlined input format for RI-SCF calculations.

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  Added the def2- family of density fitted (RI) basis sets for SCF and post-SCF calculations (courtesy of Dr. Florian Weigend).

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  On-the-fly generation for the superposition of atomic densities guess for SCF (Kevin Carter-Fenk, John Herbert).

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  Reintroduction of legacy ECPs without fitting.

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  Easy specification of basis sets on fragments, reading of basis sets from an external file (Zheng Pei and Yihan Shao).

Improvements to the DFT capabilities:

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  Support for analytic frequency calculations using meta-GGA density functionals (available only with shared-memory parallelism).

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  Support for analytic frequency calculations using resolution-of-the-identity (density-fitted) Coulomb (available only with shared-memory parallelism).

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  Improved performance of analytic partial Hessian calculations using DFT.

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  New density functionals: revM06, revM11 (Pierpaolo Morgante and Roberto Peverati).

Improvements in implicit solvation models:

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  Revised PCM tessellation grids for improved performance (John Herbert).

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  Improved performance of the general SCF program with SM$x$ solvation models (Yuezhi Mao).

New MP2 features:

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  Addition of regularized orbital-optimized second-order Møller-Plesset perturbation theory ($\kappa$-OOMP2) (Joonho Lee, Martin Head-Gordon; Section 6.6.6).

Enhancements to the coupled-cluster package:

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  Mixed-precision CCSD and EOM-CCSD (Pavel Pokhilko, Evvgeny Epifanovsky, Anna Krylov, with additional contributions from Ilya Kaliman, Kaushik Nanda, Marta Vidal, and Sonia Coriani; Sections 6.17 and 7.10.13).

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  Damped response, dynamic polarizabilities for two-electron absorption using EOM-CC (Kaushik Nanda and Anna Krylov).

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  Better handling of linear point groups in ADC and CC methods.

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  Improved performance of disk-based ADC/CC algorithms.

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  Projected and Voronoi CAP for CAP-EOM-CC/CC calculations (Ksenia Bravaya, Alexander Kunitsa; Section 7.10.9).

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  Dynamic polarizabilities for CCSD and EOM-CCSD (Kaushik Nanda, Anna Krylov; Section 7.10.21.4).

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  Improved evaluation of spin-orbit coupling constants using EOM-CC wavefunctions (Pavel Pokhilko and Anna Krylov).

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  New features for SOC calculation and analysis (Pavel Pokhilko, Anna Krylov; Section 7.10.21.2).

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  Dyson orbitals for CVS-EOM-CCSD (Marta Vidal, Sonia Coriani, Anna Krylov; Section 7.10.8).

Improvements in energy decomposition analysis methods:

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  Added electron density difference (EDD) plots and the ETS-NOCV analysis (Yuezhi Mao).

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  Added support for PCM and SMD solvation models in ALMO-EDA (Yuezhi Mao).

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  Resolved several issues that caused instabilities in MP2-EDA calculations (Yuezhi Mao).

New capabilities for explicit solvation modeling:

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  Polarizable Embedding (PE) Model for ground-state and ADC calculations (Maximilian Scheurer; Section 11.8).

Other new methods and capabilities:

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  Incremental FCI method (Paul Zimmerman).

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  Transition potential DFT for core-valence excitations.

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  Analytic evaluation of Raman intensities (Zheng Pei and Yihan Shao).