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arXiv 1602.02686cond-mat.supr-con
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超高压下H2S 200 K超导相的结构和组成：过氧化物（SH -）（H3S +）

Structure and Composition of the 200 K-Superconducting Phase of H2S under Ultrahigh Pressure: The Perovskite (SH-)(H3S+)

Elijah E. Gordon§, Ke Xu§, Hongjun Xiang, Annette Bussmann-Holder, Reinhard K. Kremer, Arndt Simon, Jürgen Köhler, Myung-Hwan Whangbo

备注：
17 pages, 6 figures, 5 tables The mistakes for the enthalpy and the free energy changes for Eq. 1 (namely, half the energy of H2 was used instead of the full energy of H2) was corrected. Our corrections of this error plus other discussion were given in a corrigendum instead of fixing the text. We added a corrigendum
发表信息：
Angew. Chem. Int. Ed., 2016, 128, 3746-3748
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摘要：

H2S在超高压（> 110 GPa）下转化为金属相，该金属相变成超导体，具有200 K的记录Tc。超导相为体心立方H_3S（Im ~ 3 m，a = 3.089 Ω），由3H_2S → 2H_3S + S分解反应生成。H2S和H2O的类比使我们得出一个非常不同的结论。众所周知的水分解成H3 O+和OH-的过程在压力下会增加几个数量级。H2S在压力下的等效行为被预期为解离，2 H2S-> H3 S + + SH-形成钙钛矿结构（SH-）（H3 S+），其由在每个A-位点具有SH-的角共享SH 6八面体组成（即，每个S8立方体的中心）。我们的DFT计算表明，钙钛矿（SH-）（H3 S+）是比H3 S的Im 3 m结构更稳定，并建议，即使在Tc的A位H原子最有可能是流动的。

英文摘要：

H2S is converted under ultrahigh pressure (> 110 GPa) to a metallic phase that becomes superconducting with a record Tc of 200 K. It has been proposed that the superconducting phase is body-centered cubic H3S ( Im3m , a = 3.089 Å) resulting from a decomposition reaction 3H2S --> 2H3S + S. The analogy of H2S and H2O leads us to a very different conclusion. The well-known dissociation of water into H3O+ and OH- increases by orders of magnitude under pressure. An equivalent behavior of H2S is anticipated under pressure with the dissociation, 2H2S --> H3S+ + SH- forming a perovskite structure (SH-)(H3S+), which consists of corner-sharing SH6 octahedra with SH- at each A-site (i.e., the center of each S8 cube). Our DFT calculations show that the perovskite (SH-)(H3S+) is thermodynamically more stable than the Im3m structure of H3S, and suggest that the A-site H atoms are most likely fluxional even at Tc.

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