A metadynamics study of the fcc–bcc phase transition in Xenon at high pressure and temperature

Abstract

To theoretically find a stable solid phase is not a trivial task even at 0K. The difficulties multiply at high temperature (T) because even more elaborate crystal structure prediction methods fail in the vicinity of the melting transition. Moreover, if the submelting phase is dynamically unstable at low T some methods cannot be applied at all. The method of metadynamics allows finding local minima of Gibbs free energy without additional simplifications. However, so far this method has been mainly used for study of pressure-induced solid–solid phase transitions and not in searching for T-induced ones. Here we study the applicability of the technique to the latter class of problems as well as to the approximate determination of the transition temperature. We apply the metadynamics method to study the solid–solid phase transition in Xe described by the Buckingham potential at high temperature and observe the fcc–bcc phase transition in a pressure–temperature range consistent with earlier results.