AN AB-INITIO INVESTIGATION OF THE MOLECULES X(2), CUX, CU(2)X AND CUX(2) (X=SI,GE, AND SN)

The molecules X(2), CuX, Cu(2)X and CuX(2) (X = Si, Ge or Sn) have been investigated by valence ab initio calculations using energy-adjusted pseudopotentials. The results for bond lengths R(e), harmonic frequencies omega(e) and dissociation energies D-e are given for the ground state of these molecules. In the case of the Cu(2)X molecules, two low-lying electronic states have been examined, (1)A(1) and B-3(1), and the singlet (1)A(1) state was found to be the ground state. The experimental dissociation energies of the CuX, Cu(2)X and CuX(2) molecules have been revised according to the molecular parameters derived in this work. A copper 19-valence-electron Dirac-Fock pseudopotential has been generated in order to check the one-valence-electron approximation in the case of the CuX molecules.