Accuracy limit of rigid 3-point water models
Accuracy limit of rigid 3-point water models
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DOI：
10.1063/1.4960175
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发表时间：
2016-08-21
影响因子：
4.4
通讯作者：
Onufriev, Alexey V.
中科院分区：
文献类型：
--
作者：
Izadi, Saeed;Onufriev, Alexey V.
经典的三点刚性水模型因其计算效率而得到最广泛的应用。最近，我们引入了一种构建经典刚性水模型的新方法[S. Izadi 等人，《物理学杂志》。化学。莱特。 5, 3863 (2014)]，它允许在与液相水分子的静电特性最相关的子空间中几乎详尽地搜索全局最优模型参数。在这里，我们应用该方法开发 3 点最佳点电荷 (OPC3) 水模型。在较宽的温度范围内再现一组全面的液体散装特性方面，OPC3 比常用的同类水模型（TIP3P 和 SPCE）更加准确。除了体积特性之外，我们还表明 OPC3 预测了水的固有电荷水合不对称性 (CHA)——水合自由能对溶质电荷符号的特征依赖性——与实验非常一致。另外两个最近的 3 点刚性水模型 TIP3PFB 和 H2ODC，各自通过自己完全不同的优化方法开发，在参数空间和整体特性精度方面都接近以 OPC3 为代表的全局精度最佳值。因此，我们认为实际上已经达到了实用 3 点刚性非极化模型的精度极限；讨论了剩余的准确性问题。由 AIP 出版社出版。
Classical 3-point rigid water models are most widely used due to their computational efficiency. Recently, we introduced a new approach to constructing classical rigid water models [S. Izadi et al., J. Phys. Chem. Lett. 5, 3863 (2014)], which permits a virtually exhaustive search for globally optimal model parameters in the sub-space that is most relevant to the electrostatic properties of the water molecule in liquid phase. Here we apply the approach to develop a 3-point Optimal Point Charge (OPC3) water model. OPC3 is significantly more accurate than the commonly used water models of same class (TIP3P and SPCE) in reproducing a comprehensive set of liquid bulk properties, over a wide range of temperatures. Beyond bulk properties, we show that OPC3 predicts the intrinsic charge hydration asymmetry (CHA) of water - a characteristic dependence of hydration free energy on the sign of the solute charge - in very close agreement with experiment. Two other recent 3-point rigid water models, TIP3PFB and H2ODC, each developed by its own, completely different optimization method, approach the global accuracy optimum represented by OPC3 in both the parameter space and accuracy of bulk properties. Thus, we argue that an accuracy limit of practical 3-point rigid non-polarizable models has effectively been reached; remaining accuracy issues are discussed. Published by AIP Publishing.