Ab initio correlation approach to a ferric wheel-like molecular cluster
Institut für Mathematische Physik, TU Braunschweig, Mendelssohnstr. 3, 38106 Braunschweig, Germany
Revised: 19 April 2006
Published online: 2 June 2006
We present an ab initio study of electronic correlation effects in a molecular cluster derived from the hexanuclear ferric wheel [ LiFe6(OCH3)12-(dbm)6] PF6. The electronic and magnetic properties of this cluster have been studied with all-electron Hartree-Fock, full-potential density functional calculations and multi-reference second-order perturbation theory. For different levels of correlation, a detailed study of the impact of the electronic correlation on the exchange parameter was feasible. As the main result, we found that the influence of the bridge oxygen atoms on the exchange parameter is less intense than the influence of the apical ligand groups, which is due to the geometry of the cluster. With respect to the cluster model approach, the experimental value of the exchange parameter was affirmed.
PACS: 31.15.Ar – Ab initio calculations / 31.25.-v – Electron correlation calculations for atoms and molecules / 75.50.Xx – Molecular magnets
© EDP Sciences, Società Italiana di Fisica, Springer-Verlag, 2006