Manz Thomas A, Chen Taoyi, Cole Daniel J, Limas Nidia Gabaldon, Fiszbein Benjamin
Department of Chemical & Materials Engineering, New Mexico State University Las Cruces New Mexico 88003-8001 USA
School of Natural and Environmental Sciences, Newcastle University Newcastle upon Tyne NE1 7RU UK.
RSC Adv. 2019 Jun 19;9(34):19297-19324. doi: 10.1039/c9ra03003d.
Polarizabilities and London dispersion forces are important to many chemical processes. Force fields for classical atomistic simulations can be constructed using atom-in-material polarizabilities and C ( = 6, 8, 9, 10…) dispersion coefficients. This article addresses the key question of how to efficiently assign these parameters to constituent atoms in a material so that properties of the whole material are better reproduced. We develop a new set of scaling laws and computational algorithms (called MCLF) to do this in an accurate and computationally efficient manner across diverse material types. We introduce a conduction limit upper bound and -scaling to describe the different behaviors of surface and buried atoms. We validate MCLF by comparing results to high-level benchmarks for isolated neutral and charged atoms, diverse diatomic molecules, various polyatomic molecules (, polyacenes, fullerenes, and small organic and inorganic molecules), and dense solids (including metallic, covalent, and ionic). We also present results for the HIV reverse transcriptase enzyme complexed with an inhibitor molecule. MCLF provides the non-directionally screened polarizabilities required to construct force fields, the directionally-screened static polarizability tensor components and eigenvalues, and environmentally screened C coefficients. Overall, MCLF has improved accuracy compared to the TS-SCS method. For TS-SCS, we compared charge partitioning methods and show DDEC6 partitioning yields more accurate results than Hirshfeld partitioning. MCLF also gives approximations for C, C, and C dispersion coefficients and quantum Drude oscillator parameters. This method should find widespread applications to parameterize classical force fields and density functional theory (DFT) + dispersion methods.
极化率和伦敦色散力对许多化学过程都很重要。经典原子模拟的力场可以使用材料中原子的极化率和C（= 6、8、9、10…）色散系数来构建。本文探讨了一个关键问题，即如何有效地将这些参数分配给材料中的组成原子，以便更好地再现整个材料的性质。我们开发了一套新的缩放定律和计算算法（称为MCLF），以在各种材料类型中以准确且计算高效的方式做到这一点。我们引入了传导极限上限和缩放来描述表面原子和埋藏原子的不同行为。我们通过将结果与孤立中性和带电原子、各种双原子分子、各种多原子分子（多并苯、富勒烯以及有机和无机小分子）以及致密固体（包括金属、共价和离子固体）的高级基准进行比较来验证MCLF。我们还展示了与抑制剂分子复合的HIV逆转录酶的结果。MCLF提供了构建力场所需的非定向屏蔽极化率、定向屏蔽静态极化率张量分量和特征值以及环境屏蔽的C系数。总体而言，与TS - SCS方法相比，MCLF的精度有所提高。对于TS - SCS，我们比较了电荷划分方法，并表明DDEC6划分比Hirshfeld划分产生更准确的结果。MCLF还给出了C、C和C色散系数以及量子德鲁德振荡器参数的近似值。该方法应在参数化经典力场和密度泛函理论（DFT）+色散方法方面得到广泛应用。
