Theoretical Study of Linear NiCO and CuCO and its Implication to Adsorption

Abstract

Abstract Ab initio RHF-MO calculations are made for the linear NiCO and CuCO clusters. The ground states of them involve Ni 3d94s1 and Cu 3d104s1 electron configurations, respectively. The orbital energies of the CO 1 π-like levels in both clusters are closely similar to each other. The CO 5σ-like level shifts toward the CO 17r-like level due to the bonding interaction of the 5σ with the metal 4s and 3dZ 2. The results are discussed in relation to the difference of the 3d-level positions and the similarity of 4s levels of Ni and Cu. For NiCO both the 4s and 3d orbitals contribute to the metal-CO binding while for CuCO only the 4 s orbital contributes to it. The present results are in agreement with the UPS experiments on adsorption.