New Features in Q-Chem 4:

Q-Chem 4.0.1 (released October 2012):

• Remote job submission in IQmol.



• High performance OpenMP implementation of coupled-cluster and EOM-CC methods.



• TDDFT gradient extended to more functionals, such as wPBE, wPBEh and CAM-B3LYP.



• Grimme's B97-D functional, popular for studying dispersion interactions.



• New functionals, e.g., self-consistent RI-B05 and RI-PSTS, for studying strongly correlated chemical systems.



• Calculations of excited state properties including transition dipole moments between different excited states in CIS and TDDFT as well as couplings for electron and energy transfer.



• Scaled nuclear charge and charged cage stabilization capabilities.



• Manual is updated to include more input examples.



• The sample input files are reorganized following the new naming convention. They are also categorized into subdirectories for easy browsing.



• The new online installer provides a simpler way to help you get started. The new package maintenance module in 4.0.1 brings upgrading to your fingertips.

Q-Chem 4.0 (released February 2012):

• Exchange-Correlation Functionals


• Density functional dispersion with implementation of the efficient Becke and Johnson’s XDM model in analytic form. (Zhengting Gan, Emil Proynov, Jing Kong, Section 4.3.7).


• Implementation of the dispersion functional vdw-DF-04 of Langreth, Lundqvist and co-workers’ (Oleg Vydrov).


• VV09, a new analytic dispersion functional based on vdw-DF-04 (Oleg Vydrov, Troy Van Voorhis, Section 4.3.5).


• Implementation of DFT-D3 Methods for improved noncovalent interactions (Shan-Ping Mao, Jeng-Da Chai, Section 4.3.8).


• ωB97X-2, a double-hybrid functional based on long range corrected B97 functional with improved account for medium and long range interactions (Jeng-Da Chai, Martin Head-Gordon, Section 4.3.9).


• XYGJ-OS, a double-hybrid functional for predictions of nonbonding interactions and thermochemistry at nearly chemical accuracy (Igor Zhang, Xin Xu, William A. Goddard, III, Yousung Jung, Section 4.3.9).


• Calculation of near-edge X-ray absorption with short-range corrected DFT (Nick Besley, Section 6.3.3).


• Improved TDDFT prediction with implementation of asymptotically corrected exchange-correlation potential (TDDFT/TDA with LB94) (Yu-Chuan Su, Jeng-Da Chai, Section 4.3.10).


• Nondynamic correlation in DFT with efficient RI implementation of Becke-05 model in fully analytic formulation. (Emil Proynov, Yihan Shao, Fenglai Liu, Jing Kong, Section 4.3.3).


• Implementation of meta-GGA functionals TPSS and its hybrid version TPSSh (Fenglai Liu) and the revPBE86 GGA functional (Oleg Vydrov).


• Implementation of double hybrid functional B2PLYP-D (Jeng-Da Chai).


• Implementation of Mori-Sánchez-Cohen-Yang (MCY2) hyper-GGA functional (Fenglai Liu).


• SOGGA, SOGGA11 and SOGGA11-X family of GGA functionals (Roberto Peverati,
  Yan Zhao, Don Truhlar).
  
  
• M08-HX and M08-SO suites of high HF exchange meta-GGA functionals (Yan Zhao,
  Don Truhlar).


• M11-L and M11 suites of meta-GGA functionals (Roberto Peverati, Yan Zhao, Don
  Truhlar).

• DFT Algorithms


• Fast numerical integration of exchange-correlation with mrXC (multiresolution exchange-correlation) Shawn Brown, Laszlo Fusti-Molnar, Nicholas J. Russ, Chun-Min Chang, Jing Kong, Section 4.4.7).


• Efficient computation of the exchange-correlation part of the dual basis DFT (Zhengting Gan, Jing Kong, Section 4.5.5).


• Fast DFT calculation with ‘triple jumps’ between different sizes of basis set and grid and different levels of functional (Jia Deng, Andrew Gilbert, Peter M. W. Gill, Section 4.8).


• Faster DFT and HF calculation with atomic resolution of the identity (ARI) algorithms (Alex Sodt, Martin Head-Gordon.)

• POST-HF: Coupled Cluster and Equation of Motion


• Significantly enhanced coupled-cluster code rewritten for better performance and multicore systems for many modules (energy and gradient for CCSD, EOM-EE/SF/IP/EACCSD, CCSD(T) energy). (Evgeny Epifanovsky, Michael Wormit, Tomasz Kuz, Arik Landau, Dmitri Zuev, Kirill Khistyaev, Ilya Kaliman, Anna Krylov, Andreas Dreuw, Chapters 5 and 6 (the new code is named CCMAN2).


• Fast and accurate coupled-cluster calculations with frozen natural orbitals (Arik Landau, Dmitri Zuev, Anna Krylov, Section refsec: FNOCC).

• POST-HF: Strong Correlation


• Perfect Quadruples and Perfect Hextuples methods for strong correlation problems (John Parkhill, Martin Head-Gordon, Section 5.6.1).


• Coupled Cluster Valence Bond (CCVB) and related methods for multiple bond breaking (David Small, Keith Lawler, Martin Head-Gordon, Section 5.13).

• DFT Excited States and Charge Transfer


• Nuclear gradients of excited states with TDDFT (Yihan Shao, Fenglai Liu, Zhengting Gan, Chao-Ping Hsu, Andreas Dreuw, Martin Head-Gordon, Jing Kong, Section 6.3.1).


• Direct coupling of charged states for the study of charge transfer reactions (Zhi-Qiang You, Chao-Ping Hsu, Section 10.17.2).


• Analytical excited-state Hessian in TDDFT within Tamm-Dancoff approximation (Jie Liu, Wanzhen Liang, Section 6.3.5).


• Obtaining an excited state self-consistently with MOM (maximum overlap method) (Andrew Gilbert, Nick Besley, Peter M. W. Gill, Section 6.5).


• Calculation of reactions with configuration interactions of charge-constrained states with constrained DFT (Qin Wu, Benjamin Kaduk, Troy Van Voorhis, Section 4.9).


• Overlap analysis of the charge transfer in a excited state with TDDFT (Nick Besley, Section 6.3.2).


• Localizing diabatic states with Boys or Edmiston-Ruedenberg localization scheme for charge or energy transfer (Joe Subotnik, Ryan Steele, Neil Shenvi, Alex Sodt, Section 10.17.1.2).

• Wavefunction-Based Excited States


• Correlated excited states with the perturbation-theory based, size consistent ADC scheme of second order(Michael Wormit, Andreas Dreuw, Section 6.7).


• Restricted active space spin- flip method for multireference ground states and multi-electron excited states (Paul Zimmerman, Franziska Bell, David Casanova, Martin Head-Gordon, Section 6.2.4).


• Implementation of non-collinear formulation extends SF-TDDFT to a broader set of functionals and improves its accuracy (Yihan Shao, Yves Bernard, Anna Krylov, Section 6.3).

• Solvation


• Smooth solvation energy surface with switching/Gaussian polarizable continuum medium PCM) solvation models for QM and QM/MM calculations (Adrian W. Lange, John Herbert, Sections 10.2.2 and 10.2.4).


• The original COSMO solvation model by Klamt and Schüürmann with DFT energy and gradient (ported by Yihan Shao, Section 10.2.8).

• Large Systems


• Accurate and fast energy computation for large systems including polarizable explicit solvation for ground and excited states with effective fragment potential using DFT/TDDFT, CCSD/EOM-CCSD, as well as CIS and CIS(D); library of effective fragments for common solvents; energy gradient for EFP-EFP systems (Vitalii Vanovschi, Debashree Ghosh, Ilya Kaliman, Dmytro Kosenkov, Chris Williams, John Herbert, Mark Gordon, Michael Schmidt, Yihan Shao, Lyudmila Slipchenko, Anna Krylov, Chapter 12)

• Optimizations, Vibrations and Dynamics


• Freezing and Growing String Methods for efficient automatic reaction path finding (Andrew Behn, Paul Zimmerman, Alex Bell, Martin Head-Gordon, Section 9.5).


• Exact, quantum mechanical treatment of nuclear motions at equilibrium with path integral methods (Ryan Steele, Section 9.8).


• Calculation of local vibrational modes of interest with partial Hessian vibrational analysis (Nick Besley, Section 10.5.3).


• Ab initio dynamics with extrapolated z-vector techniques for MP2 and/or dual-basis methods (Ryan Steele, Section 4.7.5).


• Quasiclassical ab initio molecular dynamics (Daniel Lambrecht, Martin Head-Gordon, Section 9.7.4).

• Analytical Tools


• Analysis of metal oxidation states via localized orbital bonding analysis (Alex Thom, Eric Sundstrom, Martin Head-Gordon, Section 10.3.4).


• Improved robustness of IRC code (intrinsic reaction coordinate following) (Martin Head-Gordon).


• Hirshfeld population analysis (Sina Yeganeh, Section 10.3.1).


• Visualization of noncovalent bonding using Johnson and Yang’s algorithm (Yihan Shao, Section 10.9.5).


• ESP on a grid for transition density (Yihan Shao, Section 10.10).

• Support for Modern Computing Platforms


• Better performance for multicore systems with shared-memory parallel DFT/HF (Zhengting Gan, Yihan Shao, Jing Kong) and RI-MP2 (Matthew Goldey, Martin Head-Gordon)(Section 5.12).


• Accelerating RI-MP2 calculation with GPU (graphic processing unit) (Roberto Olivares-Amaya, Mark A. Watson, Richard G. Edgar, Leslie Vogt, Yihan Shao, Alan Aspuru-Guzik, Section 5.5.3).

• Graphic User Interface


• Support of new IQmol, a free GUI designed by Andrew Gilbert at Australian National University. For more information on IQmol, visit www.iqmol.org.

More details on the new features of Q-Chem 4 can be found in the Version 4 User's Guide.