In this paper, we have performed a crystal structure screening and properties prediction framework within the noncentrosymmetric AMX₂ system, which arises from the intercalation of elements in transition metal dichalcogenides. After rigorous evaluations of thermodynamic and dynamic stability, we have refined our initial structure pool of 504 crystals to a focused set of 48 promising candidates. Analysis of their electronic properties has revealed that 23 of these crystals exhibit semiconducting behavior. The results on electron–phonon coupling and band calculations indicate that most of the remaining 25 crystals are superconducting topological nodal line or Weyl semimetals. Additionally, we find that β-InNbSe₂ in the AMX₂ family can serve as an excellent candidate to explore topological nodal lines and Lifshitz transitions. Furthermore, we also extended the thermodynamic stability analysis to higher temperatures. Ultimately, we have successfully synthesized β-InNbSe₂ with a stoichiometric ratio of 1:1:2 experimentally and characterized its superconducting properties. This study represents a systematic foray into the identification of new superconducting and topological materials within the noncentrosymmetric AMX₂ family. This screening framework can be extended to other quasi two-dimensional systems.

中文翻译：

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插层诱导过渡金属二硫化物中非中心对称超导体的晶体结构设计与合成


在本文中，我们在非中心对称 AMX₂ 系统中进行了晶体结构筛选和性质预测框架，该框架由过渡金属二硫化物中元素的嵌入产生。在对热力学和动态稳定性进行严格评估后，我们将 504 个晶体的初始结构库细化为一组 48 个有前途的候选晶体。对其电子特性的分析表明，其中 23 种晶体表现出半导体行为。电子-声子耦合和能带计算的结果表明，其余 25 种晶体中的大多数是超导拓扑节点线或 Weyl 半金属。此外，我们发现 AMX₂ 家族中的 β-InNbSe₂ 可以作为探索拓扑节点线和 Lifshitz 转变的绝佳候选者。此外，我们还将热力学稳定性分析扩展到更高的温度。最终，我们成功地通过实验合成了化学计量比为 1：1：2 的 β-InNbSe₂，并表征了其超导性能。这项研究代表了对非中心对称 AMX₂ 系列中新型超导和拓扑材料鉴定的系统性尝试。这个筛选框架可以扩展到其他准二维系统。