Abstract A new approach for evaluating Hellmann–Feynman forces within a non-local potential is introduced. Particularly, the case of Hellmann–Feynman theorem applied within density functional theory in combination with nonlocal ab-initio pseudopotentials, discretized by the finite-element method, is discussed in detail. The validity of the new approach is verified using test calculations on simple molecules and the convergence properties (w.r.t. the DFT loop) are analyzed. A comparison to other previously published approaches to Hellmann–Feynman forces calculations is shown to document that the new approach mitigates, for l -dependent as well as for separable forms of nonlocal pseudopotentials, the efficiency and/or accuracy problems arising in the methods published so far.

中文翻译：

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评估非局部赝势内的赫尔曼-费曼力

摘要 介绍了一种评估非局部势内赫尔曼-费曼力的新方法。特别地，详细讨论了在密度泛函理论中应用的 Hellmann-Feynman 定理与非局部 ab-initio 赝势相结合的情况，由有限元方法离散化。使用简单分子的测试计算验证了新方法的有效性，并分析了收敛特性（与 DFT 循环）。与其他先前发表的 Hellmann-Feynman 力计算方法的比较表明，新方法减轻了 l 依赖以及可分离形式的非局部赝势，在已发表的方法中出现的效率和/或准确性问题。远的。