X-ray diffraction indicates that the structure of the recently discovered carbonaceous sulfur hydride (C–S–H) room-temperature superconductor is derived from previously established van der Waals compounds found in the H₂S–H₂ and CH₄–H₂ systems. Crystals of the superconducting phase were produced by a photochemical synthesis technique, leading to the superconducting critical temperature T_c of 288 K at 267 GPa. X-ray diffraction patterns measured from 124 to 178 GPa, within the pressure range of the superconducting phase, are consistent with an orthorhombic structure derived from the Al₂Cu-type determined for (H₂S)₂H₂ and (CH₄)₂H₂ that differs from those predicted and observed for the S–H system at these pressures. The formation and stability of the C–S–H compound can be understood in terms of the close similarity in effective volumes of the H₂S and CH₄ components, and denser carbon-bearing S–H phases may form at higher pressures. The results are crucial for understanding the very high superconducting T_c found in the C–S–H system at megabar pressures.

中文翻译：

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C-S-H室温超导体的X射线衍射和状态方程

X 射线衍射表明，最近发现的碳质氢化硫 (C–S–H) 室温超导体的结构源自先前在 H ₂ S–H ₂和 CH ₄ –H _{2 中}发现的范德华化合物系统。超导相的晶体是通过光化学合成技术生产的，导致在 267 GPa下的超导临界温度T _c为 288 K。在超导相的压力范围内，从 124 到 178 GPa 测量的 X 射线衍射图与从 Al ₂ Cu 型衍生的斜方晶结构一致（H ₂ S）₂ H₂和 (CH ₄ ) ₂ H ₂与在这些压力下对 S-H 系统预测和观察到的不同。C-S-H 化合物的形成和稳定性可以通过 H ₂ S 和 CH ₄组分的有效体积的密切相似性来理解，并且在更高的压力下可能会形成更密集的含碳 S-H 相。结果对于理解非常高的超导关键牛逼_Ç在兆帕压力的C-S-H系统中找到。