Laboratory for Systems Biology and Medicine, Research Center for Advanced Science and Technology, the University of Tokyo, 4-6-1 Komaba, Meguro-ku, Tokyo 153-8904, Japan.
J Chem Inf Model. 2021 Mar 22;61(3):1172-1179. doi: 10.1021/acs.jcim.0c01169. Epub 2021 Feb 12.
In this study, we modified Lennard-Jones (LJ) parameters and point-charge parameters of the DREIDING force field (the modified force-field model is named DREIDING-UT). While the original LJ parameters of DREIDING were derived through an analytical formula to reproduce the potential depths and the equilibrium lengths of the Buckingham potentials of DREIDING/X6, the modified LJ parameters were derived through the least square fitting of the Buckingham potentials. Because the Gasteiger-Marsili (GM) charges of the original DREIDING underestimated electrostatic interactions, we replaced it with the restrained electrostatic potential (RESP) charges calculated from the ab initio wavefunctions, taking the dynamic electron correlation and solvation effects into account. To confirm how the modified force field works, we conducted molecular dynamics (MD) simulations of typical liquids. It was found that the densities and self-diffusion coefficients of the DREIDING-UT model agreed with the experimental ones much better than those of the original model.
在这项研究中，我们修改了 Lennard-Jones（LJ）参数和 Dreiding 力场的点电荷参数（修改后的力场模型名为 Dreiding-UT）。Dreiding 的原始 LJ 参数是通过解析公式推导出来的，以再现 Dreiding/X6 的 Buckingham 势的势深和平衡长度，而修改后的 LJ 参数则是通过 Buckingham 势的最小二乘拟合推导出来的。由于原始 Dreiding 的 Gasteiger-Marsili（GM）电荷低估了静电相互作用，我们用从头计算波函数计算的受约束静电势（RESP）电荷取代了它，考虑了动态电子相关和溶剂化效应。为了确认修改后的力场如何工作，我们对典型液体进行了分子动力学（MD）模拟。结果发现，Dreiding-UT 模型的密度和自扩散系数与实验值的一致性比原始模型要好得多。
