Novel Superconducting Phases of HCl and HBr under High Pressure: An Ab Initio Study

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• 作者：Changbo Chen ; Ying Xu ; Xiuping Sun ; Sihan Wang
• 刊名：Journal of Physical Chemistry C
• 出版年：2015
• 出版时间：July 30, 2015
• 年：2015
• 卷：119
• 期：30
• 页码：17039-17043
• 全文大小：380K
• ISSN：1932-7455

文摘

The novel superconducting C2/m phases of HCl and HBr were predicted using the developed particle swarm optimization algorithm for crystal structure prediction. The calculated results showed that the phase transition from P-1 to C2/m phases occurred at 250 and 120 GPa for HCl and HBr, respectively. Hydrogen bond symmetrization was observed in the newly predicted C2/m phase. No imaginary phonon frequencies in the whole Brillouin zone indicated that the C2/m phases of HCl and HBr were dynamically stable. In addition, the C2/m phase of HBr was the most stable structure, which rejected the earlier hypotheses of elemental decomposition into bromine and hydrogen. Perturbative linear response calculations predicted that the critical temperature T_c of the C2/m phase of HCl could reach 20 K at 250 GPa.