We present the results of a theoretical study of the structural phase transformations of ZnS under high pressure, using first-principles pseudopotential and full-potential linear muffin-tin orbital methods, in which the semicore Zn d electrons are treated as valence states. The zinc-blende, NaCl and cinnabar forms of ZnS have been considered. The structural properties and the band structures of these systems have also been studied. In the case of the FP-LMTO approach, an optimal choice of the empty spheres, atomic radii and filling percentage is introduced, which gives results in excellent agreement with those of the present pseudopotential method. It has been found that cinnabar phase is not a stable phase in ZnS under high pressure. The cinnabar phase is predicted to be a semiconductor with a direct band gap of about 3.6 eV.

J. Phys.: Condens. Matter 10 5069-5080   1998