Room‐temperature superconductivity has been a long‐standing goal in the scientific community. For computational predictions, thermodynamic stability plays a critical role. Here, a high‐throughput screening is performed to study high‐pressure ternary clathrate hydrides with hitherto unexplored compositions. Two thermodynamically stable room‐temperature superconductors in the Li─Na─H system, based on the type‐I and type‐II clathrate structure types, both exhibiting superconducting critical temperatures (Tc’s) exceeding 300 K under high pressure are uncovered. Remarkably, the type‐II structure, Li2NaH17, exhibits the highest Tc of 357 K at 220 GPa among all the reported thermodynamically stable hydrides. Random structure searches show that type‐II clathrate structures can also be stabilized with hydrogen deficiencies which lower the Tc. Superconductivity is shown to be the result of a Van‐Hove‐like singularity which can be tuned by the hydrogen content.

中文翻译：

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高压下 Li─Na 氢化物中热力学稳定的室温超导体的预测


室温超导一直是科学界的一个长期目标。对于计算预测，热力学稳定性起着关键作用。在这里，进行了高通量筛选，以研究具有迄今为止未探索成分的高压三元笼状氢化物。在 Li─Na─H 系统中发现了两个热力学稳定的室温超导体，基于 I 型和 II 型笼状结构类型，在高压下均表现出超过 300 K 的超导临界温度 （Tc）。值得注意的是，II 型结构 Li2NaH17 在所有报道的热力学稳定氢化物中表现出最高的 Tc，在 220 GPa 时为 357 K。随机结构搜索表明，II 型笼状结构也可以在氢缺乏的情况下稳定，从而降低 Tc。超导性被证明是类似范霍夫的奇点的结果，可以通过氢含量进行调整。