Stabilization of Si60 cage structure

A comprehensive search for the stable geometries of bare Si60 and Si60 supported on a C60 fullerene was carried out using first principles calculations based on density functional theory. In contrast to previous theoretical studies and in agreement with recent experiments, we show that Si60 and C(60)@Si(60) clusters are unstable in the fullerenelike cage structure. However, Si60 cage can be stabilized by including within it, as endohedral units, small magic clusters such as Al12X (X=Si, Ge, Sn, Pb) and Ba@Si(20).