Cholesky decomposition-based multiconfiguration second-order perturbation theory (CD-CASPT2): Application to the spin-state energetics of Co-III(diiminato)(NPh)

Summary, in English

The electronic structure and low-lying electronic states of a Co-III(diiminato)(NPh) complex have been studied using mulficonfigurational wave function theory (CASSCF/CASPT2) The results have been compared to those obtained with density functional theory. The best agreement with ab initio results is obtained with a modified B3LYP functional containing a reduced amount (15%) of Hartree-Fock exchange. A relativistic basis set with 869 functions has been employed in the most extensive ab initio calculations, where a Cholesky decomposition technique was used to overcome problems arising from the large size of the two-electron integral matrix. It is shown that this approximation reproduces results obtained with the full integral set to a high accuracy, thus opening the possibility to use this approach to perform multiconfigurational wave-function-based quantum chemistry on much larger systems relative to what has been possible until now.

• Author: Francesco Aquilante; Per-Åke Malmqvist; Thomas Pedersen; Abhik Ghosh; Björn Roos
• Department/s: Computational Chemistry
• Publishing year: 2008
• Language: English
• Pages: 694-702
• Publication/Series: Journal of Chemical Theory and Computation
• Volume: 4
• Issue: 5
• Links: http://dx.doi.org/10.1021/ct700263h
• Document type: Journal article
• Publisher: The American Chemical Society (ACS)
• Topic: Theoretical Chemistry (including Computational Chemistry)
• Status: Published
• ISBN/ISSN/Other: ISSN: 1549-9618