Stabilization ofSi60Cage Structure

Abstract

A comprehensive search for the stable geometries of bare ${\mathrm{S}\mathrm{i}}_{60}$ and ${\mathrm{S}\mathrm{i}}_{60}$ supported on a ${\mathrm{C}}_{60}$ 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 ${\mathrm{S}\mathrm{i}}_{60}$ and ${\mathrm{C}}_{60}@{\mathrm{S}\mathrm{i}}_{60}$ clusters are unstable in the fullerenelike cage structure. However, ${\mathrm{S}\mathrm{i}}_{60}$ cage can be stabilized by including within it, as endohedral units, small magic clusters such as ${\mathrm{A}\mathrm{l}}_{12}X$ ($X=\mathrm{S}\mathrm{i}$, Ge, Sn, Pb) and $\mathrm{B}\mathrm{a}@{\mathrm{S}\mathrm{i}}_{20}$.