采用非自洽杂化泛函精确高效计算固体中的原子力
Accurate and efficient calculation of atomic forces in solids with non-self-consistent hybrid functionals
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中文总结 AI 辅助
该研究针对杂化泛函计算成本高的问题，提出采用Quantum ESPRESSO中基于DFPT的非自洽杂化泛函计算原子力的方法，可降低成本且结果精度接近自洽计算，为固体原子力计算提供高效替代方案。
中文摘要 AI 辅助
杂化泛函通常在广义Kohn-Sham框架内自洽使用，非局域Fock交换算符的计算使杂化泛函计算（尤其采用平面波基组时）计算成本高昂。本文研究非自洽杂化泛函计算的优势，重点关注原子力的计算。利用Quantum ESPRESSO软件包中实现的密度泛函微扰理论（DFPT），计算因非自洽性产生的解析力项。因此，非自洽杂化力计算由采用局域或半局域泛函的自洽DFPT计算，加上一次Fock交换算符的计算组成。这总体降低了计算成本，尤其适用于需要密集布里渊区采样的固体。此外，结构参数结果几乎不受非自洽性影响，振动频率通常在0.5%以内一致，使非自洽计算成为一种有吸引力的替代方案。
英文摘要
Hybrid functionals are routinely employed self-consistently within the generalized Kohn-Sham framework. The evaluation of the nonlocal Fock exchange operator makes hybrid functional calculations computationally expensive, in particular with plane-wave basis sets. Here, we investigate the advantages of non-self-consistent hybrid functional calculations, focusing on the evaluation of atomic forces. The analytical force terms that arise due to non-self-consistency are computed using density functional perturbation theory (DFPT), as implemented within the Quantum ESPRESSO distribution. A non-self-consistent hybrid force calculation thus consists of self-consistent DFPT calculations with a local or semi-local functional and a single evaluation of the Fock exchange operator. The overall computational cost is, thereby, reduced in general, especially for solids that require a dense Brillouin-zone sampling. Moreover, results for structural parameters are barely affected by self-consistency, and vibrational frequencies are typically agreeing within 0.5%, thus making non-self-consistent calculations an interesting alternative.
