Symmetrized-basis LASTO calculations of defects in CdTe and ZnTe

The electronic structures of defects (vacancies and donor-vacancy pair) in CdTe and ZnTe are studied with a full-potential linearized augmented Slater-type orbital (LASTO) code. A symmetrized basis is constructed, which improves the computation efficiency of the LASTO code by two orders of magnitude when applied to large supercells with high point symmetry. Thus, we can model defects in CdTe via a large supercell (up to 128 atoms) with only modest computation effort. The lattice relaxation, the formation energy, and the energy position of defect levels for various charged states are determined. The theoretical results are compared with available experimental data and previous theoretical studies.