Theoretical study of ionic silicon clusters

The atomic structures of Sin, Sin+ and Sin2+ (n=2-6) have been studied by using MNDO method. A series of equilibrium structures have been obtained, the most stable ones are determined. Sin, Sin+ and Sin2+ have the common magic numbers which are 4, 5 and 6, but the corresponding equilibrium structures are different. The results suggest that it is unreasonable to deduce the structures of ionic silicon clusters from those of neutral silicon clusters and that charging can change the structures of atomic clusters. Moreover, several new equilibrium structures are also given.