Potential energy surfaces of NbCO

Potential energy surfaces for the low-lying electronic states of the linear niobium carbon monoxide (NbCO) complex have been studied using the complete active space multi-configuration self-consistent field (CAS-MCSCF) followed by multi-reference singles+doubles configuration interaction (MRSDCI). The 6Σ+ electronic state was found to be the ground state of Nb–CO, with a binding energy of 1.11 eV at the highest level of theory. The nature of bonding is discussed in terms of the wave function composition and the Mulliken populations.