title: Inclusion of the ligand field contribution in a polarizable molecular mechanics: SIBFA-LF.
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.
authors.affiliation: Laboratoire de Chimie Théorique, UMR 7616, Université P. & M. Curie, Case Courrier 137, 4, place Jussieu, 75252 Paris, Cedex 05, France.
authors.forename: Jean-Philip
authors.initials: JP
authors.lastname: Piquemal
authors.forename: Ben
authors.initials: B
authors.lastname: Williams-Hubbard
authors.forename: Natalie
authors.initials: N
authors.lastname: Fey
authors.forename: Robert J
authors.initials: RJ
authors.lastname: Deeth
authors.forename: Nohad
authors.initials: N
authors.lastname: Gresh
authors.forename: Claude
authors.initials: C
authors.lastname: Giessner-Prettre