Are Quasi-One Dimensional Structures of Si Stable?

The stability of quasi-one-dimensional structures of Si is investigated using a generalized tightbinding molecular-dynamics scheme. Our results show that these structures can be stable provided that their geometries consist of a core of fourfold coordinated atoms, surrounded by a threefold coordinated outer surface incorporating one of the most stable reconstructions of bulk Si. Recent experimental works reporting on the synthesis of Si nanowires support these findings.