High-pressure phase transition of cesium chloride and cesium bromide

Physical Chemistry Chemical Physics Pub Date: 2014-07-10 DOI: 10.1039/C4CP02452D

Abstract

The high-symmetry cubic cesium chloride (CsCl) structure with a space group of Pm[3 with combining macron]m (Z = 1) is one of the prototypical AB-type compounds, which is shared with cesium halides and many binary metallic alloys. The study of high-pressure evolution of the CsCl phase is of fundamental importance in helping to understand the structural sequence and principles of crystallography. Here, we have systematically investigated the high-pressure structural transition of cesium halides up to 200 GPa using an effective CALYPSO algorithm. Strikingly, we have predicted several thermodynamically favored high-pressure phases for cesium chloride and cesium bromide (CsBr). Further electronic calculations indicate that CsCl and CsBr become metallic via band-gap closure at strong compression. The current predictions have broad implications for other AB-type compounds that likely harbor similar novel high-pressure behavior.

Graphical abstract: High-pressure phase transition of cesium chloride and cesium bromide
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