Positron energy levels in zinc chalcogenides ZnS, ZnSe, and ZnTe

The self-consistent electron densities and the corresponding positron states are calculated for the zinc chalcogenides, ZnS, ZnSe and ZnTe, in the local-density approximation of the density-functional formalism. The calculations are performed with the full-potential linearized augmented plane-wave (FP-LAPW) method. The emphasis of this work is on the energy levels of the delocalized positron and the electron chemical potential. These energies determine quantities such as the positron and positronium work functions and the deformation potentials which are important parameters in slow-positron-beam experiments.