AIMMS Division of Molecular Toxicology, Department of Chemistry and Pharmaceutical Sciences, Faculty of Science , Vrije Universiteit Amsterdam , De Boelelaan 1108 , 1081 HZ Amsterdam , the Netherlands.
J Chem Theory Comput. 2019 Mar 12;15(3):1875-1883. doi: 10.1021/acs.jctc.8b01105. Epub 2019 Feb 14.
In this work we propose a strategy based on quantum mechanical (QM) calculations to parametrize a polarizable force field for use in molecular dynamics (MD) simulations. We investigate the use of multiple atoms-in-molecules (AIM) strategies to partition QM determined molecular electron densities into atomic subregions. The partitioned atomic densities are subsequently used to compute atomic dispersion coefficients from effective exchange-hole-dipole moment (XDM) calculations. In order to derive values for the repulsive van der Waals parameters from first principles, we use a simple volume relation to scale effective atomic radii. Explicit inclusion of higher order dispersion coefficients was tested for a series of alkanes, and we show that combining C and C attractive terms together with a C repulsive potential yields satisfying models when used in combination with our van der Waals parameters and electrostatic and bonded parameters as directly obtained from quantum calculations as well. This result highlights that explicit inclusion of higher order dispersion terms could be viable in simulation, and it suggests that currently available QM analysis methods allow for first-principles parametrization of molecular mechanics models.
在这项工作中，我们提出了一种基于量子力学（QM）计算的策略，用于参数化极化力场，以用于分子动力学（MD）模拟。我们研究了使用多种原子在分子（AIM）策略将 QM 确定的分子电子密度分配到原子子区域。然后，使用有效交换孔偶极矩（XDM）计算来计算分区原子密度的原子色散系数。为了从第一性原理推导出排斥范德华参数的值，我们使用简单的体积关系来缩放有效原子半径。我们对一系列烷烃进行了高阶色散系数的显式包含测试，并表明当与我们的范德华参数以及静电和键合参数结合使用时，将 C 和 C 吸引项组合在一起，并使用 C 排斥势，可以得到令人满意的模型，这些参数直接从量子计算中获得。这一结果表明，在模拟中显式包含高阶色散项是可行的，并且表明目前可用的 QM 分析方法允许对分子力学模型进行第一性原理参数化。
