Study on superconducting Li-Se-H hydrides

The structures, stabilities and superconducting properties of LiSeHn (n = 4-10) hydrides at 150-300 GPa were studied by the genetic algorithm (GA) and DFT calculation method. Three stable stoichiometries of LiSeH4, LiSeH6 and LiSeH10 were uncovered under high pressure. Four other metastable stoichiometries of LiSeH5, LiSeH7, LiSeH8, and LiSeH9 were also studied. By analyzing the electronic band structure and electronic density of states, C2 LiSeH4, Pmm2 LiSeH6 and C2 LiSeH10 were all found to be metal phases above 150 GPa. Electron-phonon coupling calculations showed that C2 LiSeH4 and Pmm2 LiSeH6 were promising superconductors. The predicted T-c values of C2 LiSeH4 and Pmm2 LiSeH6 were 77 K at 200 GPa and 111 K at 250 GPa, respectively.