Self-interaction-corrected local density approximationpseudopotential calculations of the structural phase transformationsof ZnO and ZnS under high pressure

Abstract

The structural phase transformations under high pressure of ZnO and ZnS have been investigated by using theVogel-Krüger-Pollmann (VKP) scheme, in which theelectronic self-interaction correction to the local densityapproximation (LDA) is introduced in a non-self-consistentmanner within the pseudopotential approach. In these calculations, I have used highly optimized pseudopotentials and a plane-waveexpansion of the wavefunctions. Moreover, the electronic structuresof the zinc-blende (ZB) and rock-salt (RS) phases ofboth compounds have been similarly calculated. It has been foundthat the VKP scheme provides a highly improved description, relative to the LDA results, for the structural and electronicstructure properties of the considered systems. However, theso-calculated transition pressures of the ZB-to-RStransition for both ZnO and ZnS are found to besignificantly larger than the experimental data. RS-ZnO ispredicted to be an indirect-gap semiconductor, with a wide band gap of 4.2 eV.