LCAO-Xα-Force Study on Stable Structures of Si6and Si10Clusters

Stable structures of the Si 6 and the Si 10 microclusters have been calculated using LCAO-Xα-force method. The calculated structures of the Si 6 and the Si 10 clusters resemble a regular octahedron and a tetrahedron, respectively. In both clusters, triangles constituted of the (111)-surface atoms of the crystalline silicon contract by 20% in length compared to those of the crystal. This contraction is attributed to the interaction between dangling bonds and important for silicon microclusters of any size.