Countless molecular dynamics studies have relied on available ion and water force field parameters to model aqueous electrolyte solutions. The TIP4P/2005 model has proven itself to be among the best rigid water force fields, whereas many of the most successful ion parameters were optimized in combination with SPC/E, TIP3P, or TIP4P/Ew water. Many researchers have combined these ions with TIP4P/2005, hoping to leverage the strengths of both parameter sets. To assess if this widely used approach is justified and to provide a guide in selecting ion parameters, we investigated the transferability of various commonly used monovalent and multivalent ion parameters to the TIP4P/2005 water model. The transferability is evaluated in terms of ion hydration free energy, hydration radius, coordination number, and self-diffusion coefficient at infinite dilution. For selected ion parameters, we also investigated density, ion pairing, chemical potential, and mean ionic activity coefficients at finite concentrations. We found that not all ions are equally transferable to TIP4P/2005 without compromising their performance. In particular, ions optimized for TIP3P water were found to be poorly transferable to TIP4P/2005, whereas ions optimized for TIP4P/Ew water provided nearly perfect transferability. The latter ions also showed good overall agreement with experimental values. The one exception is that no combination of ion parameters and water model considered here was found to accurately reproduce experimental self-diffusion coefficients. Additionally, we found that cations optimized for SPC/E and TIP3P water displayed consistent underpredictions in the hydration free energy, whereas anions consistently overpredicted the hydration free energy.

中文翻译：

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使用分子动力学模拟，将离子参数转移到TIP4P / 2005水模型中。

无数的分子动力学研究依靠可用的离子和水力场参数来模拟电解质水溶液。TIP4P / 2005模型已证明自己是最佳的刚性水力场之一，而许多最成功的离子参数已与SPC / E，TIP3P或TIP4P / Ew水结合使用进行了优化。许多研究人员将这些离子与TIP4P / 2005结合使用，希望利用这两个参数集的优势。为了评估这种广泛使用的方法是否合理，并为选择离子参数提供指导，我们研究了各种常用的单价和多价离子参数到TIP4P / 2005水模型的可转移性。根据离子水合自由能，水合半径，配位数，和无限稀释时的自扩散系数。对于选定的离子参数，我们还研究了在有限浓度下的密度，离子对，化学势和平均离子活度系数。我们发现并非所有离子都能平等地转移到TIP4P / 2005，而不会影响其性能。特别是，发现针对TIP3P水优化的离子很难转移到TIP4P / 2005，而针对TIP4P / Ew水优化的离子则提供了近乎完美的转移性。后者离子也显示出与实验值良好的总体一致性。一个例外是，未发现此处考虑的离子参数和水模型的组合能够准确地再现实验性自扩散系数。另外，