发表机构
Center of Novel Technologies, University of Warsaw（新技朮中心，华沙大学）
机构由 AI 辅助整理，请以论文原文为准。AI 中文总结
重新研究MgHCu3钙钛矿超导特性，用PBEsol和PBE泛函计算，发现其声子及相关性质对网格密度和泛函敏感，临界超导温度值在10至31K间，未超经典极限，建议用多种泛函审查并与实验基准测试以提供可靠TC值。
AI 中文摘要
我们使用PBEsol和PBE泛函重新研究了MgHCu3钙钛矿的晶体结构、电子结构、晶格动力学、声子色散、电子-声子耦合和超导特性。该钙钛矿相最近被提出具有42K的临界超导温度TC，略高于声子驱动超导性的经典40K极限。我们表明，尽管该假设化合物的晶体和电子结构对k点网格和所用泛函相当稳健，但声子及与声子相关的性质对所选网格密度和计算所用泛函极为敏感。相应地，此处针对不同高斯展宽计算出的临界超导温度值在约10至31K的宽范围内变化，且未超过经典极限。我们建议应使用多种泛函对该化合物及许多其他声称的高TC氢化物的性质进行全面审查，并与实验进行基准测试，以提供更可靠的TC值。
英文摘要
We reexamine the crystal structure, electronic structure, lattice dynamics, phonon dispersion, electron-phonon coupling, and superconducting properties of MgHCu3 perovskite using the PBEsol and PBE functionals. This perovskite phase was recently proposed to exhibit superconductivity with the critical superconducting temperature, TC, of 42 K, which falls slightly over the classical 40 K limit for the phonon driven superconductivity. We show that although the crystal and electronic structure of this hypothetical compound are quite robust with respect to the k point mesh and functional used, yet the phonons and phonon related properties are extremely sensitive to the density of the grid chosen as well as functional used for calculations. Correspondingly, the values of the critical superconducting temperature calculated here for different Gaussian broadenings vary in a broad range of ca. 10 to 31 K and they do not exceed the classical limit. We suggest that the properties of this and many other high TC hydrides claimed should be thoroughly scrutinized using a variety of functionals, and benchmarked with experiment, to provide more reliable values of TC.
Comments13 pages, 3 Figures, 1 Table, and Supplementary Information of 9 pages
