PHYSICA STATUS SOLIDI B-BASIC SOLID STATE PHYSICS, cilt.243, sa.2, 2006 (SCI-Expanded)
Using ab initio calculations, we predict stable small diameter silicon nanowires. The wires are constructed from the expended phases of silicon, clathrate Si(34) and Si(46) structures, and found to be energetically more favorable than the diamond type nanowires at the same diameters. Furthermore, the wires are semiconducting with band gap energy of 0.22 eV and 0.34 eV. Chemical passivation of the wires with hydrogen induces a broadening of band gap energy due to the quantum size effect and increases the hardness of the wires.