title: High-pressure phase transition of MH₃ (M: Er, Ho).
abstract: Motivated by the potential high temperature superconductivity in hydrogen-rich materials, high-pressure structures of ErH3 and HoH3 were studied by using genetic algorithm method. Our calculations indicate that both ErH3 and HoH3 transform from P-3c1 structure to a monoclinic C2/m structure at about 15 GPa, and then transforms into a cubic Fm-3m structure at about 40 GPa. ErH3 and HoH3 adopt the same P6₃/mmc structure with space group P6₃/mmc at above about 220 and 196 GPa, respectively. For ErH3, the P6₃/mmc phase is stable up to at least 300 GPa, while for HoH3, a phase transformation P6₃/mmc → Cmcm occurs at about 216 GPa, and the Cmcm phase is stable up to at least 300 GPa. The P-3c1 ErH3 and HoH3 are calculated to demonstrate non-metallic character, and the other phases are all metallic phases.
authors.affiliation: State Key Laboratory of Superhard Materials, College of Physics, Jilin University, Changchun 130012, People's Republic of China.
authors.forename: Pugeng
authors.initials: P
authors.lastname: Hou
authors.affiliation: State Key Laboratory of Superhard Materials, College of Physics, Jilin University, Changchun 130012, People's Republic of China.
authors.forename: Fubo
authors.initials: F
authors.lastname: Tian
authors.affiliation: State Key Laboratory of Superhard Materials, College of Physics, Jilin University, Changchun 130012, People's Republic of China.
authors.forename: Da
authors.initials: D
authors.lastname: Li
authors.affiliation: State Key Laboratory of Superhard Materials, College of Physics, Jilin University, Changchun 130012, People's Republic of China.
authors.forename: Binhua
authors.initials: B
authors.lastname: Chu
authors.affiliation: State Key Laboratory of Superhard Materials, College of Physics, Jilin University, Changchun 130012, People's Republic of China.
authors.forename: Zhonglong
authors.initials: Z
authors.lastname: Zhao
authors.affiliation: State Key Laboratory of Superhard Materials, College of Physics, Jilin University, Changchun 130012, People's Republic of China.
authors.forename: Bingbing
authors.initials: B
authors.lastname: Liu
authors.affiliation: State Key Laboratory of Superhard Materials, College of Physics, Jilin University, Changchun 130012, People's Republic of China.
authors.forename: Tian
authors.initials: T
authors.lastname: Cui