Dipole polarizabilities of PdN (N=2-25) clusters

The dipole polarizabilities of Pd-N (N = 2-25) clusters are studied using a scheme for decomposing the total polarizability of a system into site-specific contributions. Furthermore, the polarizabilities are partitioned into dipole and charge transfer components. The structure and size-specific aspects of the polarizabilities are analyzed. It is shown that the polarizabilities associated with the individual constituent atoms vary considerably with the structure of the cluster and the location of the atom or site within a given structure. For atoms at peripheral sites, the polarizabilities are substantially larger than atoms at the interior sites, and the more peripheral an atom is, the larger its polarizability. This indicates significant screening of the cluster interior by its surface. The oscillations in the total polarizability mainly come from charge transfer component oscillatory behavior and the later approaches the bulk polarizability per atom. The anisotropy of the total polarizability is closely related with the anisotropy of the cluster shape.