Superconducting TaH5 at high pressure

Abstract

Recently, the significant development, in the field of high-temperature superconductivity among the compressed elements hydrides (such as LaH10), opens up a door in pursuing room-temperature superconductors. Therefore, the investigations of excellent superconductivity in hydrogen-rich materials have become a hot topic of considerable interest. Herein, we explore the stabilities of compressed tantalum polyhydrides TaHn (n = 1-6) and the superconductivity by using a particle swarm optimization structure prediction methodology in combination with the first-principles electronic structure framework. As a result of structure searches, we identified a stable TaH5 compound under high pressure, which consists edge shared TaH12 polyhedra. Remarkably, within Allen-Dynes modified McMillan equation, our predicted TaH5 is a superconductor with superconducting critical temperature (Tc) of 18-23 K at 100 GPa.