The self-consistent tight-binding method: application to silicon and silicon carbide

The self-consistent tight-binding (SCTB) model proposed by Majewski and Vogl (1987) has been extended to be applicable for calculations of lattice defects in solids or disordered systems with both ionic and covalent characters that cannot be treated using other types of tight-binding theories. The precise formulation of electronic structure, total energy and atomic forces in the supercell technique has been presented. In order to apply this method to lattice defects in SiC, the parameters and functional forms have been examined so as to reproduce the basic properties of Si, SiC and C. The nature of the bonding and the phase stability in Si and SiC have been analysed by the present SCTB method.