Theoretical studies of structural and dynamical properties of one- and two-component metal clusters

Results of extensive numerical simulation studies of structural and dynamical properties of one- and two- component metal clusters of different sizes are presented and discussed. The simulations are based on semiempirical potentials that take into account the many-body character of metallic cohesion. Stable and metastable structural forms (isomers), and phases and phase changes of clusters are analyzed as a function of cluster size, material(s) and stoichiometric composition. The added richness of the possible structural forms of a two-component alloy cluster of specified stoichiometry is characterized in terms of isomers (i.e., different geometric structures) and homotops (i.e., different distributions of the component metals in a cluster of fixed geometry). The peculiarities of the meltinglike transition are correlated with the patterns of energy spectra of the isomers and homotops. The notion of the mixing coefficient, as a quantitave measure of the degree of mixing of two components in a cluster, is introduced. It is shown that for a fixed size and stoichiometry the different forms of a cluster can be grouped into classes, the energy ordering within which is defined by the mixing coefficient