Study on superconducting Li-Se-H hydrides

The structures, stabilities and superconducting properties of LiSeH (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.