OPTIMIZED JELLIUM MODEL FOR METAL-CLUSTERS

An optimized parameter-free jellium model is proposed for polyatomic c lusters. This model leads to an absolute minimum of the total energy o f a system consisting of delocalized electrons and a positive core. A double-variation method is used to determine the optimum distribution of the charge density of the cluster core and the electronic structure . The total energy of the cluster reaches a minimum under the conditio n of local electrical neutrality. Numerical calculations have been car ried out on the electronic structure in the Hartree-Fock approximation with various numbers of atoms. The electron system, with a shell stru cture, has a strong effect on the charge distribution of the positive background. Basic physical characteristics of the metal clusters calcu lated from this model are compared with experimental data and with the results of other calculations. (C) 1994 American Institute of Physics .