SEMICONDUCTOR EFFECTIVE CHARGES AND DIELECTRIC-CONSTANTS IN THE TIGHT-BINDING APPROACH

The calculation of the effective charges and dielectric constants of c ommon III-V and LI-VI semiconductors is revised. The expectation value of the position operator on the sp(3)s tight-binding basis set is ex pressed in terms of a semiconductor-class-related constant, which is f ound to be related to the covalency of the compounds. Within this appr oach, the computed dielectric properties are in very good agreement wi th experiment.