Group V accepters in CdTe:: Ab initio calculation of lattice relaxation and the electric-field gradient

Using the linearized augmented plane wave method, the self-consistent electronic structure of the group V accepters N, P, As, and Sb in CdTe is calculated in order to derive the electric field gradient (EFG) at the neighboring Cd site. The agreement between theory and experiment is very good and, due to the high sensitivity of the EFG on the local structure, it is evidence of the accuracy of the calculated lattice relaxation. The dependence of the EFG on the charge state of the group V accepters is discussed in terms of the calculated electronic density of states.