A comparative density functional study of the high-pressure phases of solid ZnX, CdX, and HgX (X = S, Se, and Te): Trends and relativistic effects

The pressure dependence of bulk properties for the group 12 chalcogenides MX (M = Zn, Cd, Hg; X = S, Se, Te) from density functional theory are presented. Energy-volume and corresponding enthalpy-pressure relationships are determined to obtain the transition paths and properties of various high-pressure phases. The influence of relativistic effects is discussed with the aim to explain the unique behavior of the mercury chalcogenides as compared to the lighter zinc and cadmium homologs at high pressures. The neglect of relativistic effects leads to a more CdX like behavior of the mercury chalcogenides, and the pronounced change in coordination of the cinnabar phase at high pressures is due to relativistic effects. (C) 2012 American Institute of Physics. [http://dx.doi.org/10.1063/1.4730300]