Iron-sulfur bond covalency from electronic structure calculations for classical iron-sulfur clusters
2014 Wiley Periodicals, Inc.
| Veröffentlicht in: | Journal of computational chemistry. - 1984. - 35(2014), 7 vom: 15. März, Seite 540-52 |
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| Format: | Online-Aufsatz |
| Sprache: | English |
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2014
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| Zugriff auf das übergeordnete Werk: | Journal of computational chemistry |
| Schlagworte: | Journal Article Research Support, N.I.H., Extramural Research Support, Non-U.S. Gov't Research Support, U.S. Gov't, Non-P.H.S. FeS bond covalency FeS metalloproteins S donation X-ray absorption spectroscopy ab initio WFN calculations density functional theory mehr... |
| Zusammenfassung: | 2014 Wiley Periodicals, Inc. The covalent character of iron-sulfur bonds is a fundamental electronic structural feature for understanding the electronic and magnetic properties and the reactivity of biological and biomimetic iron-sulfur clusters. Conceptually, bond covalency obtained from X-ray absorption spectroscopy (XAS) can be directly related to orbital compositions from electronic structure calculations, providing a standard for evaluation of density functional theoretical methods. Typically, a combination of functional and basis set that optimally reproduces experimental bond covalency is chosen, but its dependence on the population analysis method is often neglected, despite its important role in deriving theoretical bond covalency. In this study of iron tetrathiolates, and classical [2Fe-2S] and [4Fe-4S] clusters with only thiolate ligands, we find that orbital compositions can vary significantly depending on whether they are derived from frontier orbitals, spin densities, or electron sharing indexes from "Átoms in Molecules" (ÁIM) theory. The benefits and limitations of Mulliken, Minimum Basis Set Mulliken, Natural, Coefficients-Squared, Hirshfeld, and AIM population analyses are described using ab initio wave function-based (QCISD) and experimental (S K-edge XAS) bond covalency. We find that the AIM theory coupled with a triple-ζ basis set and the hybrid functional B(5%HF)P86 gives the most reasonable electronic structure for the studied Fe-S clusters |
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| Beschreibung: | Date Completed 03.10.2014 Date Revised 17.02.2014 published: Print-Electronic Citation Status MEDLINE |
| ISSN: | 1096-987X |
| DOI: | 10.1002/jcc.23518 |