title: Bonding in Cu, Ag, and Au clusters: relativistic effects, trends, and surprises.
abstract: Electronic structure and bonding in anionic coinage metal clusters are investigated via density-functional calculations, focusing on an extensive set of isomers of Cu(-)(7), Ag(-)(7), and Au(-)(7). While the ground states of Cu(-)(7) and Ag(-)(7) are three dimensional (3D), that of Au(-)(7) is planar, separated from the optimal 3D isomer by 0.5 eV. The simulated thermally weighted photoabsorption spectrum of Au(-)(7) is dominated by planar structures, and it agrees well with the measured one. The propensity of Au(-)(N) clusters to favor planar structures (with N as large as 13) is correlated with strong hybridization of the atomic 5d and 6s orbitals due to relativistic effects.
authors.affiliation: School of Physics, Georgia Institute of Technology, Atlanta, Georgia 30332-0430, USA.
authors.forename: Hannu
authors.initials: H
authors.lastname: Häkkinen
authors.forename: Michael
authors.initials: M
authors.lastname: Moseler
authors.forename: Uzi
authors.initials: U
authors.lastname: Landman