Ab initio study of MArn+ (M = Cu, Ag, and Au, n=1-3)

The equilibrium geometries, stabilities and populations of the clusters mentioned in the title of this paper were studied at HF, MP2 and CCSD(T) levels. The natural bond orbital (NBO) analysis was performed to explore the nature of the interactions. The electron correlation and relativistic effects on the geometry and stability were investigated at the CCSD(T) level and both effects stabilize the clusters.