An ab initio study of WO3under pressure up to 30 GPa

Abstract

High-pressure polymorphs of WO3have been studied with a first-principles pseudopotential method. Themedium-range (0.01–20 GPa) and high-range (20–30 GPa) polymorphs have beencharacterized and are compared with recent experimental results. The main newfeature is the appearance of a sevenfold coordinated tungsten in the high-pressurepolymorph. The subtle phase transitions that were induced from Raman spectraevolutions have not been confirmed. However, changes in the W–O distances andO–W–O and W–O–W angles may explain the changes in Raman spectra.