AB INITIO CALCULATIONS OF DIMETAL COMPLEXES USING RELATIVISTIC EFFECTIVE CORE POTENTIALS

Author Institution: Department of Chemistry, The Ohio State University; Institut Le Bel, Universit\'{e} Louis Pasteur, Laboratoire de Chimie Quantique, E.R. 139 du CNRSThe complexes studied were dimolybdenum and direhenium complexes such $Re_{2}$$Cl_{8}^{-2}$. Atomic basis sets were optimized for molybdenum, rhenium, chlorine, oxygen, and phosphorus for use with Christiansen effective core potentials. Hartree-Fock self-consistent field (SCF) calculations for these complexes were performed. Recently the Ohio State multi-configuration self-consistent field (SCF)calculations for these complexes were performed. Recently the Ohio State multi-configuration self-consistent field (MCSCF) programs have been modified to incorporate relativistic effective core potentials. The known quadruple metal-metal bond was investigated and is under analysis in our present and future calculations. While the SCF calculations did not show a quadruple metal-metal bond; the MCSCF calculations showed this bond, based on molecular orbital coefficients and Mullikan population analysis. Calculations were performed on some excited states and compared to experiment. Monovalent complex cations were also studied in order to compare with the photoelectron spectra. Final calculations are at the Cl level and include spin-orbit matrix elements