title: Structure and shape variations in intermediate-size copper clusters.
abstract: Using extensive, unbiased searches based on density-functional theory, we explore the structural evolution of Cu(n) clusters over the size range n=8-20. For n=8-16, the optimal structures are plateletlike, consisting of two layers, with the atoms in each layer forming a trigonal bonding network similar to that found in smaller, planar clusters (n<or=6). For n=17 and beyond, there is a transition to compact structures containing an icosahedral 13-atom core. The calculated ground-state structures are significantly different from those predicted earlier in studies based on empirical and semiempirical potentials. The evolution of the structure and shape of the preferred configuration of Cu(n), n<or=20, is shown to be nearly identical to that found for Na clusters, indicating a shell-model-type behavior in this size range.
authors.affiliation: Department of Physics, Central Michigan University, Mount Pleasant, Michigan 48859, USA.
authors.forename: Mingli
authors.initials: M
authors.lastname: Yang
authors.forename: Koblar A
authors.initials: KA
authors.lastname: Jackson
authors.forename: Christof
authors.initials: C
authors.lastname: Koehler
authors.forename: Thomas
authors.initials: T
authors.lastname: Frauenheim
authors.forename: Julius
authors.initials: J
authors.lastname: Jellinek