Quantum-mechanical modeling of the high-pressure state equations of ZnO and ZnS

Abstract

Equations of state (EOS) for the high-pressure phases of ZnO and ZnS have been determined by carrying out ab initio perturbed-ion calculations. The results are used to examine different empirical EOS formalisms proposed for experimental P-V data. The generalized Vinet EOS is shown to be highly sensitive to the uncertainties in experimental data, thus providing a poor extrapolation for the properties at zero pressure. Contrarily, the modified Birch-Murnaghan EOS predicts zero-pressure properties that agree with ab initio calculations.