MICROSCOPIC STUDY OF THE PRESSURE-INDUCED STRUCTURAL PHASE-TRANSITIONOF ZNTE

We have performed ab initio pseudopotential calculations within the lo cal-density approximation to investigate the structural phase transiti on of ZnTe under pressure. By calculating the total energy, atomic for ces, and stress tensors, we theoretically determine the structural pha se transition of ZnTe from the zinc-blende to the cinnabar to the orth orhombic structure under increasing pressure, which agrees well with e xperiment. We demonstrate that rotation of bonds toward lower-symmetry positions occurs at the critical pressure to relieve excessive strain .