Structural and electronic properties of metal-encapsulated silicon clusters in a large size range

Structural and electronic properties of metal-doped silicon clusters MSi(n)s (M=W, Zr, Os, Pt, Co, etc.) in a large size range of 8 less than or equal to n less than or equal to 20 are investigated via ab initio calculations. Different from a recent experimental suggestion that the metal atom is endohedral in MSin, we reveal that the formation of endohedral structure strongly depends on the size of the Si-n cluster. Two novel structures of the chemically stable endohedral species are manifested. The suitable M@Si-n building blocks of self-assembly materials vary in the range of 10 less than or equal to n less than or equal to 16. The thermodynamical magic numbers are found to coincide with the chemical magic numbers for five clusters.