REINTRODUCTION OF IONIC STRUCTURE IN THE SELF-CONSISTENT JELLIUM MODEL FOR METAL-CLUSTERS - PSEUDOPOTENTIAL PERTURBATION-THEORY

The structureless self-consistent jellium model for simple metal clust ers is corrected by reintroducing the ionic structure via second-order pseudopotential perturbation theory. It is found that this formulatio n is enough to bring this approximate treatment into a quantitative ag reement with fully fledged ab initio Car-Parrinello structure optimiza tion. Furthermore, the ionic perturbation leads to a substantial impro vement in the description of the optical response.