Anomalous behavior of the semiconducting gap in (formula presented) from first-principles calculations

Abstract

Several crystal structures of tungsten trioxide have been studied with a first-principles pseudopotential method. The electronic band gap increases significantly with the distortion of the octahedra that are the building blocks of the various crystal structures. Moreover, the tilting of the octahedra in the more complex structures leads to a strong increase of the gap upon compression. © 1999 The American Physical Society.