Departamento de Química , Universidad Autónoma Metropolitana-Iztapalapa. Av. San Rafael Atlixco 186, Col. Vicentina , Ciudad de México 09340 , México.
Centro Universitario de los Valles , Universidad de Guadalajara , Carretera Guadalajara-Ameca km. 45.4 , Ameca , Jalisco 46600 , México.
J Chem Theory Comput. 2018 Nov 13;14(11):5949-5958. doi: 10.1021/acs.jctc.8b00554. Epub 2018 Oct 22.
The Hirshfeld charges are linearly increased to reproduce the experimental dielectric constant of 10 polar solvents having values between 13 (pyridine) and 182 ( N-methylformamide). The OPLS/AA force field is used to obtain the new parameters. The surface tension and liquid density are also target properties to determine the new nonbonding parameters. The charge scaling factor is between 1.2 and 1.3. In addition, properties that were not used in the parametrization procedure, such as the heat of vaporization, self-diffusion coefficient, shear viscosity, isothermal compressibility, and volumetric expansion coefficient are obtained. Binary mixtures of amide/water and amide/amide are also studied. The original parameters of OPLS/AA, CGenFF, and GAFF force fields are evaluated. The TIP4P/ε force field is used to simulate water. The results from this work with the new parameters, for both pure components and binary mixtures, are in better agreement with experimental data than those obtained with the original values for most of the calculated properties. The maximum density of N-methylformamide in aqueous solutions is correctly predicted only with the new parameters. The high value of the dielectric constant of acetamide, formamide, and N-methylformamide is discussed in terms of the chain formation from the hydrogen bond interactions.
Hirshfeld 电荷呈线性增加，以再现实验介电常数为 10 的 10 种极性溶剂，这些溶剂的值在 13（吡啶）和 182（N-甲基甲酰胺）之间。使用 OPLS/AA 力场获得新参数。表面张力和液体密度也是目标性质，用于确定新的非键参数。电荷缩放因子在 1.2 到 1.3 之间。此外，还获得了未用于参数化过程的性质，例如蒸发焓、自扩散系数、剪切粘度、等温压缩系数和体积膨胀系数。酰胺/水和酰胺/酰胺的二元混合物也进行了研究。评估了 OPLS/AA、CGenFF 和 GAFF 力场的原始参数。TIP4P/ε 力场用于模拟水。与原始值相比，使用新参数对纯组分和二元混合物进行的大多数计算性质的计算结果与实验数据更为吻合。仅使用新参数才能正确预测水合 N-甲基甲酰胺的最大密度。讨论了乙酰胺、甲酰胺和 N-甲基甲酰胺的高介电常数是如何通过氢键相互作用形成链来实现的。
