Stable structures for Si20 clusters -: art. no. 023201

Full-potential linear-muffin-tin-orbital molecular-dynamics calculations have been performed to investigate the structures and energies of Si-20 clusters. Among the selected 15 stable structures for Si-20, the most stable structure is constructed by stacking Si-9 tricapped trigonal prisms (TTP) subunits. Its symmetry is C-2 Another structure with almost the same binding energy as the ground-state structure is also obtained by stacking Si-9 tricapped trigonal prisms subunits, but its symmetry is D-3h The subunit is just the ground-state structure of Si-10, with C-3v symmetry. The ground-state structure of Si-20 can interpret the fragmentation experimental result and the absorption property of ammonia molecules for Si-20(+).