Study on Atom Packing and Electrical Properties of Tin (n=2-10) Clusters with GA&DFTB Calculations

Abstract

The researches of atom packing and electronic properties of titanium clusters are of great significance in producing highly pure Ti particles. The geometrical structures as well as electronic properties of Tin(n=2-10) clusters were obtained by using density functional tight binding (DFTB) simulations being combined with genetic algorithms (GA). The binding energy, the second differences in energy, HOMO-LUMO gap, and Mulliken populations were calculated and discussed. The results show that these Ti clusters containing three or less atoms have planar structures or a linear form, while those containing more than four atoms present three-dimensional geometries. There exist different packing structures including tetrahedron, octahedron, and decahedron. As the atom number increases in these clusters, the configures are formed by capping the atoms on the (111) facets of these clusters with octahedron and decahedron geometries. The binding for the electrons is stronger in the icosahedral cluster than that in those clusters having the other configurations. Mulliken populations present significant differences as the atom packing changes in these clusters.