Ab initio studies on the electronic structure of the complexes containing Mo——S bond using relativistic effective core potentials

An ab initio calculation was performed on the electronic structures of MoS,MoSandMoSusing relativistic effective core potential（RECP）for molybdenum,and non-relativistic ECPfor sulfur.We predicted that the equilibrium bond length and the dissociation energy of MoS inground state are 3.89 a.u.and 4.67 eV,respectively,and that the bond is a triple-bond.The groundstate of MoSin Td symmetry isAand π-bonding dominates σ-donation in the molybdenum-sulfur interaction.The MoSis a model contracted from bi-nuclear sulfur-bridged clusters,andthe bonding orbitals 1 b,1bg and 1bg make the dominant contribution to the stabilization of sulfur-bridged species.