title: Structural metatransition of energetically tangled crystalline phases.
abstract: We solve the longstanding puzzle of pressure induced structural evolution of SnSe using a swarm structure search method combined with first-principles phonon and kinetic barrier calculations. Our results identify a dynamic set of nearly degenerate crystalline SnSe phases that are separated by low kinetic barriers and undergo an unusual type of structural transitions characterized by a dynamically changing mix of the constituent phases. We introduce a new concept of structural metatransition to highlight the transitional nature of such phase transitions. Our theoretical prediction is corroborated by X-ray diffraction measurements, and this intriguing phenomenon offers insights into the enigmatic property variations of SnSe under pressure. This work raises prospects of considerably improving characterization and understanding of intrinsic multiphase crystals and their dynamic evolution.
authors.affiliation: Laboratory of Clean Energy Technology, Changchun University of Science and Technology, Changchun 130022, China and Physics and HiPSEC, University of Nevada, Las Vegas, Nevada 89154, USA. chen@physics.unlv.edu and Department of Materials Science, State Key Laboratory of Superhard Materials, and Key Laboratory of Automobile Materials of MOE, Jilin University, Changchun 130012, China. liquan777@jlu.edu.cn.
authors.forename: Dan
authors.initials: D
authors.lastname: Zhou
authors.affiliation: Physics and HiPSEC, University of Nevada, Las Vegas, Nevada 89154, USA. chen@physics.unlv.edu and Department of Materials Science, State Key Laboratory of Superhard Materials, and Key Laboratory of Automobile Materials of MOE, Jilin University, Changchun 130012, China. liquan777@jlu.edu.cn.
authors.forename: Quan
authors.identifier: http://orcid.org/0000-0002-7724-1289
authors.initials: Q
authors.lastname: Li
authors.affiliation: Department of Materials Science, State Key Laboratory of Superhard Materials, and Key Laboratory of Automobile Materials of MOE, Jilin University, Changchun 130012, China. liquan777@jlu.edu.cn.
authors.forename: Weitao
authors.identifier: http://orcid.org/0000-0002-9028-278X
authors.initials: W
authors.lastname: Zheng
authors.affiliation: Department of Materials Science, State Key Laboratory of Superhard Materials, and Key Laboratory of Automobile Materials of MOE, Jilin University, Changchun 130012, China. liquan777@jlu.edu.cn.
authors.forename: Yanming
authors.initials: Y
authors.lastname: Ma
authors.affiliation: Physics and HiPSEC, University of Nevada, Las Vegas, Nevada 89154, USA. chen@physics.unlv.edu.
authors.forename: Changfeng
authors.initials: C
authors.lastname: Chen