paper

Decomposition of solid hydrogen bromide at high pressure

arXiv:1504.01196

Abstract

The stability of different stoichiometric H $_{n}$ Br ( $n$ =1-7) compounds under pressure are extensively studied using density functional theory calculations. Five new energetically stable stoichiometries of H $_{2}$ Br, H $_{3}$ Br, H $_{4}$ Br, H $_{5}$ Br, and H $_{7}$ Br were uncovered at high pressure. The results show that HBr is stable below 64 GPa, then decomposes into new compound H $_{2}$ Br and Br $_{2}$ molecular crystal. For H $_{2}$ Br and H $_{3}$ Br compounds, they were found to become stable above 30 GPa and 8 GPa, respectively. In addition, we accidentally discovered the triangular H $_{3}^{+}$ species in H $_{5}$ Br compounds at 100 GPa. Further electron-phonon coupling calculations predicted that hydrogen-rich H $_{2}$ Br and H $_{4}$ Br compounds are superconductors with critical temperature of superconductivity $T_{c}$ of 12.1 K and 2.4 K at 240 GPa, respectively.

15 pages, 5 figures