采用更新后范德华半径的Tkatchenko-Scheffler色散方法的性能：对含碱金属体系的重要性
Performance of Tkatchenko-Scheffler Dispersion Method with Updated van der Waals Radii: Importance for Alkali-Containing Systems
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中文总结 AI 辅助
本研究对比TS_2018、TS_alkali与TS_2009及非局域多体色散方法对含碱金属等材料的结构预测性能，发现TS_2009对碱金属体系过结合，TS_2018及相关修正方案可改善该问题。
中文摘要 AI 辅助
用于计算色散相互作用的Tkatchenko-Scheffler（TS）成对方法，是纳入半局域和混合密度泛函计算中缺失的长程范德华贡献的广泛应用方法。尽管该方法已通过多次改进纳入多体项，其原始形式仍作为高效且稳健的方法具有重要意义，尤其适用于有机和/或绝缘材料。2018年，Fedorov等人针对2009年的开创性工作报告了更新后的范德华半径。本研究将TS方法与更新后的范德华半径（缩写为TS_2018）结合半局域Perdew-Burke-Ernzerhof密度泛函，用于半导体和绝缘材料的结构预测，并与非局域多体色散方法及原始TS方法（TS_2009）进行对比。研究特别关注含碱金属的材料，TS_2009方法对这类材料表现出显著的过结合特性，这与预测原子结构时可能出现的大误差相关。我们还考虑了一种更窄范围的修正方案（TS_alkali），仅对碱金属原子进行校正，其余部分仍与TS_2009兼容。我们采用5个碱金属二聚体的结合能曲线，结合随机相位近似评估TS_2009和TS_2018方法；再利用45种有实验参考数据的无机固体化合物，以及3种广泛研究的含Cs卤化物钙钛矿CsPbX₃（X=Cl、Br、I），对比TS_2018、TS_alkali与TS_2009及超出成对的非局域多体色散方法的性能，发现后者也能给出良好结果。
英文摘要
The Tkatchenko-Scheffler (TS) pairwise method to calculate dispersion interactions is a widely used approach to incorporate missing long-range van der Waals contributions in semilocal and hybrid density functional calculations. Despite numerous refinements of the approach to include many-body terms, the original formulation still remains highly relevant as an efficient and robust method, especially for organic and/or insulating materials. In 2018, Fedorov et al. reported updated van der Waals radii to the seminal work published in 2009. The present work examines the accuracy of the TS method with updated van der Waals radii (abbreviated as TS_2018), coupled with the semilocal Perdew-Burke-Ernzerhof density functional, for structural predictions of semiconducting and insulating materials in comparison to the non-local many-body dispersion method and the original TS method (TS_2009). Special attention is paid to materials containing alkali elements, for which the TS_2009 method exhibits a large overbinding, associated with potentially large errors in predicted atomic structures. We also consider a more narrow reformulation (TS_alkali) where only the the alkali atoms are corrected, so the method remains otherwise compatible with TS_2009. The binding energy curves of five alkali dimers are used to assess the TS_2009 and the TS_2018 methods in comparison to the random phase approximation. Using 45 inorganic solid compounds with available experimental reference data, as well as three widely studied, Cs-containing halide perovskites, CsPb$X_3$ ($X$ = Cl, Br, I), we then examine the performance of the TS_2018 and TS_alkali approaches compared to TS_2009 and the beyond-pairwise, nonlocal many-body dispersion method; the latter found to give good results as well.
