Phase transition and bond symmetrization associated with noble gas bond in XeO3

Abstract

The pressure-induced structural phase transition of XeO3 is studied by first principle calculations. The transition from P212121 to Pnma accompanied by a drastic reduction of volume is found at 2.18 GPa. The symmetrilized Xe−O2 bonds give rise to the better symmetry of high pressure phase. O-hopping between different possible local minima and the motion of Xe along the y axis may be responsible for phase transition. Results of electron localization function indicate that three ipsilateral Xe−O bonds lead to a lone-pair contour of Xe6+.