Structural and Electronic-Properties of Small Copper Clusters - a First Principles Study

Equilibrium geometries and electronic properties of neutral Cu-n (n = 2, 3, 4, 6, 8, 10) clusters are determined via first principles calculations which treat s and d electrons on an equal footing. Overall, we find ground state and local minimum structures similar to those of Na-n. However, Cu-n clusters tend to prefer more compact arrangements. Electronic states with atomic s-character are strongly hybridized with d-states and located mostly at the band edges. Angular decomposition of the electronic wavefunctions in Cu-n clusters shows that their shell model character is significantly less pronounced than in Na-n clusters.