Boothroyd Scientific Consulting Ltd., 71-75 Shelton Street, London WC2H 9JQ, Greater London, U.K.
Department of Chemical and Biological Engineering, University of Colorado Boulder, Boulder, Colorado 80309, United States.
J Chem Theory Comput. 2022 Jun 14;18(6):3577-3592. doi: 10.1021/acs.jctc.1c01268. Epub 2022 May 9.
Developing a sufficiently accurate classical force field representation of molecules is key to realizing the full potential of molecular simulations as a route to gaining a fundamental insight into a broad spectrum of chemical and biological phenomena. This is only possible, however, if the many complex interactions between molecules of different species in the system are accurately captured by the model. Historically, the intermolecular van der Waals (vdW) interactions have primarily been trained against densities and enthalpies of vaporization of pure (single-component) systems, with occasional usage of hydration free energies. In this study, we demonstrate how including physical property data of binary mixtures can better inform these parameters, encoding more information about the underlying physics of the system in complex chemical mixtures. To demonstrate this, we retrain a select number of Lennard-Jones parameters describing the vdW interactions of the OpenFF 1.0.0 (Parsley) fixed charge force field against training sets composed of densities and enthalpies of mixing for binary liquid mixtures as well as densities and enthalpies of vaporization of pure liquid systems and assess the performance of each of these combinations. We show that retraining against the mixture data improves the force field's ability to reproduce mixture properties, including solvation free energies, correcting some systematic errors that exist when training vdW interactions against properties of pure systems only.
开发一个足够精确的分子经典力场表示是实现分子模拟全部潜力的关键，分子模拟可以为广泛的化学和生物现象提供基本的洞察力。然而，只有当系统中不同物种分子之间的许多复杂相互作用被模型准确捕捉时，这才有可能。从历史上看，分子间范德华（vdW）相互作用主要是针对纯（单组分）系统的密度和蒸发热进行训练的，偶尔也会使用水合自由能。在这项研究中，我们展示了如何将二元混合物的物理性质数据纳入这些参数，从而更好地描述这些参数，为复杂化学混合物中的系统基础物理提供更多信息。为了证明这一点，我们重新训练了选择的一些描述 OpenFF 1.0.0（Parsley）固定电荷力场 vdW 相互作用的 Lennard-Jones 参数，这些参数是针对二元液体混合物的混合密度和焓以及纯液体系统的蒸发热和蒸气压训练集进行的，并评估了这些组合中的每一个的性能。我们表明，针对混合物数据进行重新训练可以提高力场再现混合物性质的能力，包括溶剂化自由能，纠正了仅针对纯系统性质训练 vdW 相互作用时存在的一些系统误差。
