Potential energy surfaces of RuCO

Potential energy surfaces for the low-lying electronic states of the ruthenium carbon monoxide (RuCO) molecule have been studied using the complete active space multi-configuration self-consistent field (CASMCSCF) followed by multireference singles+doubles configuration interaction (MRSDCI). Two nearly-degenerate electronic states were found as candidates for the ground state of RuCO. The nature of bonding is discussed in terms of the wave function composition and the Mulliken population analysis.