title: High-pressure phase transition of cesium chloride and cesium bromide.
abstract: The high-symmetry cubic cesium chloride (CsCl) structure with a space group of Pm3¯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.
authors.affiliation: State Key Laboratory of Superhard Materials, Jilin University, Changchun 130012, China. liquan777@jlu.edu.cn.
authors.forename: Shubo
authors.initials: S
authors.lastname: Wei
authors.forename: Chunye
authors.initials: C
authors.lastname: Zhu
authors.forename: Qian
authors.initials: Q
authors.lastname: Li
authors.forename: Yuanyuan
authors.initials: Y
authors.lastname: Zhou
authors.forename: Quan
authors.initials: Q
authors.lastname: Li
authors.forename: Yanming
authors.initials: Y
authors.lastname: Ma