GGA-Level Subsystem DFT Achieves Sub-kcal/mol Accuracy Intermolecular Interactions by Mimicking Nonlocal Functionals
GGA-Level Subsystem DFT Achieves Sub-kcal/mol Accuracy Intermolecular Interactions by Mimicking Nonlocal Functionals
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GGA 级子系统 DFT 通过模拟非局部泛函实现分子间相互作用的亚 kcal/mol 精度
DOI：
10.1021/acs.jctc.1c00283
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发表时间：
2021
影响因子：
5.5
通讯作者：
Pavanello, Michele
中科院分区：
文献类型：
--
作者：
Shao, Xuecheng;Mi, Wenhui;Pavanello, Michele
非局域动能泛函的关键特征是它们能够在高密度区域中约化为Fermas-Fermi泛函，在低密度/高约化密度梯度区域中约化为von Weizsa Fermcker泛函。这种行为是至关重要的，当这些泛函在子系统DFT模拟近似的非加性动能。我们提出了一个GGA非加性动能泛函，它模仿了非局部泛函的良好行为，保留了典型半局部泛函的计算复杂性。至关重要的是，这个功能取决于子系统间的密度重叠。新的泛函再现了Kohn-Sham DFT和基准CCSD（T）在S22-5和S66测试集中弱相互作用二聚体的相互作用能，平均绝对偏差远低于1 kcal/mol。
The key feature of nonlocal kinetic energy functionals is their ability to reduce to the Thomas-Fermi functional in the regions of high density and to the von Weizsäcker functional in the region of low-density/high reduced density gradient. This behavior is crucial when these functionals are employed in subsystem DFT simulations to approximate the nonadditive kinetic energy. We propose a GGA nonadditive kinetic energy functional which mimics the good behavior of nonlocal functionals, retaining the computational complexity of typical semilocal functionals. Crucially, this functional depends on the inter-subsystem density overlap. The new functional reproduces Kohn–Sham DFT and benchmark CCSD(T) interaction energies of weakly interacting dimers in the S22-5 and S66 test sets with a mean absolute deviation well below 1 kcal/mol.