EMPIRICAL SPDS-ASTERISK TIGHT-BINDING CALCULATION FOR CUBIC SEMICONDUCTORS - GENERAL-METHOD AND MATERIAL PARAMETERS

An empirical tight-binding method for tetrahedrally coordinated cubic materials is presented and applied to group-IV and III-V semiconductor s. The present spds method extends existing calculations by the inclu sion of all five d orbitals per atom in the basis set. On-site energie s and two-center integrals between nearest neighbors in the Hamiltonia n are fitted to measured energies, pseudopotential results, and the fr ee-electron band structure. We demonstrate excellent agreement with ps eudopotential calculations up to about 6 eV above the valence-band max imum even without inclusion of interactions with more distant atoms an d three-center integrals. The symmetry character of the Bloch function s at the X point is considerably improved by the inclusion of d orbita ls. Density of states, reduced masses, and deformation potentials are correctly reproduced.