Cheng YingXing, Verstraelen Toon
Center for Molecular Modeling (CMM), Ghent University, Technologiepark-Zwijnaarde 46, B-9052 Gent, Belgium.
J Chem Phys. 2022 Sep 28;157(12):124106. doi: 10.1063/5.0115151.
A frequency-dependent extension of the polarizable force field "Atom-Condensed Kohn-Sham density functional theory approximated to the second-order" (ACKS2) [Verstraelen et al., J. Chem. Phys. 141, 194114 (2014)] is proposed, referred to as ACKS2ω. The method enables theoretical predictions of dynamical response properties of finite systems after partitioning of the frequency-dependent molecular response function. Parameters in this model are computed simply as expectation values of an electronic wavefunction, and the hardness matrix is entirely reused from ACKS2 as an adiabatic approximation is used. A numerical validation shows that accurate models can already be obtained with atomic monopoles and dipoles. Absorption spectra of 42 organic and inorganic molecular monomers are evaluated using ACKS2ω, and our results agree well with the time-dependent DFT calculations. Also for the calculation of C dispersion coefficients, ACKS2ω closely reproduces its TDDFT reference. When parameters for ACKS2ω are derived from a PBE/aug-cc-pVDZ ground state, it reproduces experimental values for 903 organic and inorganic intermolecular pairs with an MAPE of 3.84%. Our results confirm that ACKS2ω offers a solid connection between the quantum-mechanical description of frequency-dependent response and computationally efficient force-field models.
提出了极化力场“二阶近似原子凝聚Kohn-Sham密度泛函理论”（ACKS2）[Verstraelen等人，《化学物理杂志》141, 194114 (2014)] 的频率相关扩展，称为ACKS2ω。该方法能够在对频率相关分子响应函数进行划分后，对有限系统的动力学响应特性进行理论预测。该模型中的参数简单地计算为电子波函数的期望值，并且由于使用了绝热近似，硬度矩阵完全复用自ACKS2。数值验证表明，使用原子单极子和偶极子已经可以获得精确的模型。使用ACKS2ω评估了42种有机和无机分子单体的吸收光谱，我们的结果与含时密度泛函理论计算结果吻合良好。同样，对于C色散系数的计算，ACKS2ω也能紧密重现其含时密度泛函理论参考值。当ACKS2ω的参数从PBE/aug-cc-pVDZ基态导出时，它能重现903个有机和无机分子间对的实验值，平均绝对百分比误差为3.84%。我们的结果证实，ACKS2ω在频率相关响应的量子力学描述与计算效率高的力场模型之间提供了坚实的联系。
