A summary of the technical advances that are incorporated in the fourth major release of the Q-Chem quantum chemistry program is provided, covering approximately the last seven years. These include developments in density functional theory methods and algorithms, nuclear magnetic resonance (NMR) property evaluation, coupled cluster and perturbation theories, methods for electronically excited and open-shell species, tools for treating extended environments, algorithms for walking on potential surfaces, analysis tools, energy and electron transfer modelling, parallel computing capabilities, and graphical user interfaces. In addition, a selection of example case studies that illustrate these capabilities is given. These include extensive benchmarks of the comparative accuracy of modern density functionals for bonded and non-bonded interactions, tests of attenuated second order Møller-Plesset (MP2) methods for intermolecular interactions, a variety of parallel performance benchmarks, and tests of the accuracy of implicit solvation models. Some specific chemical examples include calculations on the strongly correlated Cr2 dimer, exploring zeolite-catalysed ethane dehydrogenation, energy decomposition analysis of a charged ter-molecular complex arising from glycerol photoionisation, and natural transition orbitals for a Frenkel exciton state in a nine-unit model of a self-assembling nanotube.
Bibliographical noteFunding Information:
Electronic structure software development at Q-CHEM has been supported during the period reviewed in this paper by SBIR grants from the National Institutes of Health [grant number 2R44GM073408], [grant number 2R44GM069255], [grant number 1R43GM086987], [grant number 2R44GM076847], [grant number 2R44GM081928], [grant number 2R44GM084555], [grant number 1R43GM096678], and from the Department of Energy [grant number DE-SC0011297]. In addition, the academic research groups that have contributed to Q-CHEM have been supported within the US by grants from the Department of Energy, the National Science Foundation, and other Federal agencies, and by corresponding national agencies in other countries.
© 2014 © 2014 Taylor & Francis.
- computational modelling
- density functional theory
- electron correlation
- electronic structure theory
- quantum chemistry