A practical valence bond method : a configuration interaction method approach with perturbation theoretic facility
Copyright 2004 Wiley Periodicals, Inc. J Comput Chem 25: 472-478, 2004
| Veröffentlicht in: | Journal of computational chemistry. - 1984. - 25(2004), 4 vom: 16. März, Seite 472-8 |
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| Weitere Verfasser: | , , |
| Format: | Aufsatz |
| Sprache: | English |
| Veröffentlicht: |
2004
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| Zugriff auf das übergeordnete Werk: | Journal of computational chemistry |
| Schlagworte: | Journal Article |
| Zusammenfassung: | Copyright 2004 Wiley Periodicals, Inc. J Comput Chem 25: 472-478, 2004 The previously developed valence bond configuration interaction (VBCI) method (Wu, W.; Song, L.; Cao, Z.; Zhang, Q.; Shaik, S., J. Phys. Chem. A, 2002, 105, 2721) that borrows the general CI philosophy of the MO theory, is further extended in this article, and its methodological features are improved, resulting in three accurate and cost-effective procedures: (a) the effect of quadruplet excitation is incorporated using the Davidson correction, such that the new procedure reduces size consistency problems, with due improvement in the quality of the computational results. (b) A cost-effective procedure, named VBCI(D, S), is introduced. It includes doubly excited structures for active electrons and singly excited structures for inactive pairs. The computational results of VBCI(D, S) match those of VBCISD with much less computational effort than VBCISD. (c) Finally, a second-order perturbation theory is utilized as a means of configuration selection, and lead to considerable reduction of the computational cost, with little or no loss in accuracy. Applications of the new procedures to bond energies and barriers of chemical reactions are presented and discussed |
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| Beschreibung: | Date Completed 12.04.2004 Date Revised 21.01.2004 published: Print Citation Status PubMed-not-MEDLINE |
| ISSN: | 1096-987X |