Ground-state properties and high-pressure phase of beryllium chalcogenides BeSe, BeTe, and BeS

Abstract

We present an ab initio pseudopotential study within the local density approximation of the ground-state and high-pressure phases of BeSe, BeTe, and BeS. We analyze the zinc-blende, NaCl, CsCl, NiAs, and \ensuremath{\beta}-Sn structures. By calculating the total energy, atomic forces, and stress tensors we determine the structural parameters (lattice constants, bulk moduli, etc.) of these compounds and the transition pressure from the zinc-blende (B3) to the NiAs (B8) phase. The structural parameters and transition pressure for BeSe and BeTe compare quite well with recent experimental results. For BeS our results are predictions. \textcopyright{} 1996 The American Physical Society.