Inclusion of the ligand field contribution in a polarizable molecular mechanics: SIBFA-LF

J P Piquemal, B Williams-Hubbard, N Fey, R J Deeth, N Gresh, C Giessner-Prettre

Research output: Contribution to journalArticle (Academic Journal)peer-review

68 Citations (Scopus)

Abstract

To account for the distortion of the coordination sphere that takes place in complexes containing open-shell metal cations such as Cu(II), we implemented, in sum of interactions between fragments ab initio, computed (SIBFA) molecular mechanics, an additional contribution to take into account the ligand field splitting of the metal d orbitals. This term, based on the angular overlap model, has been parameterized for Cu(II) coordinated to oxygen and nitrogen ligands. The comparison of the results obtained from density functional theory computations on the one hand and SIBFA or SIBFA-LF on the other shows that SIBFA-LF gives geometric arrangements similar to those obtained from quantum mechanical computations. Moreover, the geometric improvement takes place without downgrading the energetic agreement obtained from SIBFA. The systems considered are Cu(II) interacting with six water molecules, four ammonia or four imidazoles, and four water plus two formate anions. (C) 2003 Wiley Periodicals, Inc.

Original languageEnglish
Pages (from-to)1963-1970
Number of pages8
JournalJournal of Computational Chemistry
Volume24
Issue number16
Publication statusPublished - Dec 2003

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