Electronic structure of the transition metal nitrides TiN, VN, and CrN

The electronic and geometric structures of the ground and low-lying excited states of TiN, VN, and CrN have been studied by ab initio MCSCF and multireference configuration interaction (CI) techniques. The ground states have the symmetries (2) Sigma(+), (3) Delta, and (4) Sigma(-), respectively, and are characterized by a triple bond with no 4s character. We report dissociation energies, vibrational frequencies, dipole moments, bond lengths, and charge distributions for a variety of electronic states and compare with experiment, where possible.