Research Institute for Interdisciplinary Science, Okayama University, Okayama 700-8530, Japan.
Department of Chemistry, Faculty of Science, Okayama University, Okayama 700-8530, Japan.
J Chem Theory Comput. 2020 Apr 14;16(4):2460-2473. doi: 10.1021/acs.jctc.9b00941. Epub 2020 Apr 1.
Most classical nonpolarizable ion potential models underestimate the solubility values of NaCl and KCl in water significantly. We determine Lennard-Jones parameters of Na, K, and Cl that reproduce the solubility as well as the hydration free energy in dilute aqueous solutions for three water potential models, SPC/E, TIP3P, and TIP4P/2005. The ion-oxygen distance in the solution and the cation-anion distance in salt are also considered in the parametrization. In addition to the target properties, the hydration enthalpy, hydration entropy, self-diffusion coefficient, coordination number, lattice energy, enthalpy of solution, density, viscosity, and number of contact ion pairs are calculated for comparison with 17 frequently used or recently developed ion potential models. The overall performance of each ion model is represented by a global score using a scheme that was originally developed for comparison of water potential models. The global score is better for our models than for the other 17 models not only because of the quite good prediction for the solubility but also because of the relatively small deviation from the experimental value for many of the other properties.
大多数经典的不可极化离子势模型严重低估了 NaCl 和 KCl 在水中的溶解度值。我们确定了 Na、K 和 Cl 的 Lennard-Jones 参数，这些参数既能重现溶解度，又能重现三种水势模型（SPC/E、TIP3P 和 TIP4P/2005）中稀水溶液的水合自由能。在参数化过程中，还考虑了溶液中的离子-氧距离和盐中的阳离子-阴离子距离。除了目标性质外，还计算了水合焓、水合熵、自扩散系数、配位数、晶格能、溶解焓、密度、粘度和接触离子对的数量，以与 17 种常用或最近开发的离子势模型进行比较。使用最初为比较水势模型而开发的方案，用全局评分来表示每个离子模型的整体性能。我们的模型的整体评分比其他 17 个模型要好，不仅因为对溶解度的预测相当好，还因为对许多其他性质的实验值的偏差相对较小。
