LAUSR

Abstract As one of the first known Weyl semimetals, TaP exhibits intriguing topological properties and has received intensive attention. We investigated the evolution of atomic and electronic structure of TaP in a wide pressure range from 0 GPa to 200 GPa via first-principles calculations combined with intelligent particle swarm optimization. Three pressure-induced phase transformations were identified, following the transition sequence of I 4 1 md (α-phase) →  Pmmn (β-phase) →  P 2 1 / c (γ-phase) →  Pm- 3 m (δ-phase) with transition pressure of 67 GPa, 90 GPa, and 125 GPa, respectively. The coordination number of Ta in α-phase, γ-phase, and δ-phase is 6, 7, and 8, respectively, indicating a denser packing under compression. All these newly pressure-stabilized structures were dynamically stable at both high and ambient pressure. Interestingly, we observed a semimetal to metal transition in the β phase. This work would shed light on further studies and applications of TaAs-class Weyl semimetals under compression or extreme condition.