Study of electronic spectra of free-base porphin and Mg-porphin : comprehensive comparison of variety of ab initio, DFT, and semiempirical methods
(c) 2004 Wiley Periodicals, Inc.
Veröffentlicht in: | Journal of computational chemistry. - 1984. - 26(2005), 3 vom: 01. Feb., Seite 294-303 |
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Weitere Verfasser: | , |
Format: | Aufsatz |
Sprache: | English |
Veröffentlicht: |
2005
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Zugriff auf das übergeordnete Werk: | Journal of computational chemistry |
Schlagworte: | Journal Article |
Zusammenfassung: | (c) 2004 Wiley Periodicals, Inc. SAC (symmetry adapted cluster)/SAC-CI and CASPT2 (multiconfigurational second-order perturbation theory) electron excitation spectra of free-base porphin and magnesium-porphin were determined using basis set functions augmented by both the polarization and diffuse functions-6-31+G(d). Such basis is recommended for correct description of the spectra because diffuse functions play fundamental roles in the formation of Rydberg MOs. The obtained results indicated that already the lowest roots in A(u), B(1u), B(2g), and B(3g) irreducible representations display Rydberg character. The calculated spectra are in a good agreement with both experimental and recently calculated electronic transitions. It is concluded that the SAC/SAC-CI level spectral lines are significantly affected by configuration selection when energy thresholds 5.0 x 10(-6) and 5.0 x 10(-7) a.u. are used for the determination of ground and excited state properties |
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Beschreibung: | Date Completed 03.05.2005 Date Revised 03.01.2005 published: Print Citation Status PubMed-not-MEDLINE |
ISSN: | 1096-987X |