LOCALIZED-ORBITAL HARTREE-FOCK DESCRIPTION OF ALKALI-METAL CLUSTERS

We propose a new variational method, based on the ab initio Hartree-Fock methods, for the purpose of calculating efficiently both the equilibrium geometry and the stability of alkali-metal microclusters. Applying this method to lithium clusters, up to Li36, we are able to find a close correlation between the observed magic numbers and the calculated stable cluster size. Furthermore, we find that lithium clusters larger than Li26 have an ordered structure, while clusters smaller than this do not. This is suggestive of the evolution of the clusters to the bulk structure of solid lithium. © 1990 The American Physical Society.