The ligand field spectrum of the hexafluorochromate (III) anion: An ab initio study including correlation effects

Autor:	Lg Vanquickenborne, Kristine Pierloot
Rok vydání:	1990
Předmět:	Ligand field theory Electronic correlation Ab initio quantum chemistry methods Chemistry Computational chemistry Excited state Ab initio General Physics and Astronomy Electronic structure Complete active space Physical and Theoretical Chemistry Configuration interaction Molecular physics
Zdroj:	The Journal of Chemical Physics. 93:4154-4163
ISSN:	1089-7690 0021-9606
DOI:	10.1063/1.458748
Popis:	The ground and ligand field excited states of CrF3−6 have been studied, using different Gaussian basis sets of atomic natural orbitals. Each state was first optimized separately in a complete active space self‐consistent field (CASSCF) calculation, including three active electrons in the 2t2g and 4eg shells. Further correlation was then added by using either a singles and doubles configuration interaction approach (SDCI) or by the average coupled pair functional method (ACPF) with the CASSCF configuration space as the reference space. Thereby the number of correlated electrons was raised up to 15. It is shown that the quartet–quartet transitions, corresponding to a 2t2g→4eg excitation, are described already very accurately at the CASSCF level. Further improvement of the 4A2g→4T2g transition was obtained by extending the CI treatment so as to include the F 2p electrons from the 1t2g,3eg, and finally also from the 6a1g shell. For the intraconfigurational t32g quartet–doublet transitions on the other hand, t...
Databáze:	OpenAIRE
Externí odkaz:	https://explore.openaire.eu/search/publication?articleId=doi_________::dd495f153417728aec5efdcd3b0b371f https://doi.org/10.1063/1.458748 Zobrazit plný text záznamu