Journal of Physical Chemistry A, Vol.101, No.43, 8107-8114, 1997
Calculated structures of MO22+, MN2, and MP2 (M = Mo, W)
Ab initio calculations of MoN2, MoP2, MoO22+ WN2, WP2, and WO22+ were performed using quasi relativistic effective core potentials and MP2, B3LYP, CCSD(T) and CASPT2 methodologies. Multiple local minima were found on the potential energy surfaces of the Various spin states of the nitrides and phosphides. The nitrides all are either above the dissociation limit or only very slightly below it. The phosphides are energetically below the dissociation limit. The bond angles of the oxoions, as well as the phosphides and nitrides at some spin states, are nearly tetrahedral. Several minima with narrow (35-65 degrees) bond angles, representing a side-on bond of a partially dissociated N-2 or P-2 molecule to the metal atom, were found as well. The oxoions and phosphides are believed to have an autonomous, gas-phase existence. The character of the bonding molecular orbitals has been analyzed.