1.3.1 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 (K. Fenk, J. 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 (Z. Pei and Y. Shao).

Improvements to the DFT capabilities:

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  Support for analytic frequency calculations using meta-GGA density functinoals (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 (P. Morgante and R. Peverati).

Improvements in implicit solvation models:

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

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  Improved performance of the general SCF program with SMx solvation models (Y. Mao).

New MP2 features:

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  Addition of regularized orbital-optimized second-order Møller-Plesset perturbation theory ($\kappa$-OOMP2) (J. Lee, M. Head-Gordon; Section 6.6.5).

Enhancements to the coupled-cluster package:

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  Mixed-precision CCSD and EOM-CCSD (P. Pokhilko, E. Epifanovsky, A.I. Krylov, with contributions from I. Kaliman, K. Nanda, M. Vidal, S. Coriani; Sections 6.15 and 7.8.10).

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  Damped response, dynamic polarizabilities for two-electron absorption using EOM-CC (K. Nanda and A.I. Krylov).

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  Improved evaluation of spin-orbit coupling constants across EOM-CC states (P. Pokhilko and A.I. 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 (K. Bravaya, A. Kunitsa; Section 7.8.7).

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  Dynamic polarizabilities for CCSD and EOM-CCSD (K. Nanda, A.I. Krylov; Section 7.8.18.4).

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  New feaures for SOC calculation and analysis (P. Pokhilko, A.I. Krylov; Section 7.8.18.2).

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  Dyson orbitals for CVS-EOM-CCSD (M. Vidal, S. Coriani, A.I. Krylov; Section 7.8.6).

Improvements in energy decomposition analysis methods:

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

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

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

New capabilities for explicit solvation modeling:

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  Polarizable Embedding (PE) Model for ground-state and ADC calculations (M. Scheurer; Section 12.8).

Other new methods and capabilities:

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  Incremental FCI method (P. Zimmerman).

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  Transition potential DFT for core-valence excitations.

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  Analytic evaluation of Raman intensities (Z. Pei and Y. Shao).