高压下的超导“方钠石”状笼形氢化钙
Superconductive "sodalite"-like clathrate calcium hydride at high pressures
摘要：
富氢化合物有望在高压下成为高温超导体。最近的理论氢化物结构实现高压超导主要由H2碎片。通过一个系统的调查与不同的氢含量的钙离子，使用粒子游泳优化结构搜索，我们表明，在化学计量学的CaH 6的体心立方结构与氢，形成不寻常的“方钠石”笼含有enclethrated钙稳定以上的压力150 GPa。这种结构的稳定性来源于两个H2接受由Ca提供的电子，形成“H4”单元作为三维方钠石笼的构建中的构建块。这种独特的结构部分占据了区域中心的简并轨道。由此产生的动态Jahn-Teller效应有助于增强电子-声子耦合并导致CaH 6的超导电性。由Eliashberg方程的解得到的超导临界温度（Tc）为220-235 K（150 GPa），是迄今为止所研究的超导体中最高的。
英文摘要：
Hydrogen-rich compounds hold promise as high-temperature superconductors under high pressures. Recent theoretical hydride structures on achieving high-pressure superconductivity are composed mainly of H2 fragments. Through a systematic investigation of Ca hydrides with different hydrogen contents using particle-swam optimization structural search, we show that in the stoichiometry CaH6 a body-centred cubic structure with hydrogen that forms unusual "sodalite" cages containing enclathrated Ca stabilizes above pressure 150 GPa. The stability of this structure is derived from the acceptance by two H2 of electrons donated by Ca forming a "H4" unit as the building block in the construction of the 3-dimensional sodalite cage. This unique structure has a partial occupation of the degenerated orbitals at the zone centre. The resultant dynamic Jahn-Teller effect helps to enhance electron-phonon coupling and leads to superconductivity of CaH6. A superconducting critical temperature (Tc) of 220-235 K at 150 GPa obtained from the solution of the Eliashberg equations is the highest among all hydrides studied thus far.
机构、总结、中文摘要均由AI分析而来，可能存在错误，请以论文正文为准。
