Superconducting high pressure phase of GeH4

Abstract

Through ab initio evolutionary methodology, we reveal a high-pressure metallic structure of GeH_4 with C2/c symmetry. This structure contains novel " H_2 " units. Enthalpy calculations suggest a wide decomposition ( Ge + H_2) pressure range of 0-196 GPa, above which the C2/c structure is stable. Perturbative linear response calculations for C2/c at 220 GPa predict a large electron-phonon coupling parameter of 1. 12 and a resulting superconducting critical temperature of 64 K. 明,GeH_4在压力低于196 GPa时分解为单质Ge和H_2,而在高于这一压力时C2/c结构稳定存在.在220 GPa压力下,线性响应微扰理论的计算结果表明,C2/c结构的电子一声子相互作用参数为1.12,其超导转变温度达到64 K.