Image states in metal clusters

Image states for small clusters from a full quantum-mechanical many-body calculations were investigated. It was found that in contrast to surfaces, nanoclusters contain a finite number of image states, that were subject to quantum confinement effects. Image state energies and wave functions for spherical jellium clusters up to 186 atoms were calculated in GW approximation, where G is the Green's function and W is the dynamically screened Coulomb interaction, which by construction contains the dynamic long-range correlation effects giving rise to image effects. A model potential that captures the correct asymptotic decay of the image potential and yields images states in agreement with GW approach was also developed.