Chemistry Department , University of California, Davis , Davis , California 95616 , United States.
Departments of Physics & Astronomy and Biological Sciences , California State University , Los Angeles , California 90032 , United States.
J Phys Chem B. 2019 Aug 15;123(32):7061-7073. doi: 10.1021/acs.jpcb.9b05455. Epub 2019 Jul 31.
In this work, we investigate whether experimental surface tension measurements, which are less sensitive to quantum and self-polarization corrections, are able to replace the usual reliance on the heat of vaporization as experimental reference data for fitting force field models of molecular liquids. To test this hypothesis, we develop the fitting protocol necessary to utilize surface tension measurements in the ForceBalance optimization procedure to determine revised parameters for both three-point and four-point water models TIP3P-ST and TIP4P-ST. We find that the incorporation of surface tension in the fit results in a rigid three-point model that reproduces the correct temperature of maximum density of water for the first time but also leads to overstructuring of the liquid and less accurate transport properties. The rigid four-point TIP4P-ST model is highly accurate for a broad range of thermodynamic and kinetic properties, with similar performance compared to recently developed four-point water models. The results show surface tension to be a useful fitting property in general, especially when self-polarization corrections or nuclear quantum corrections are not readily available for correcting the heat of vaporization as is the case for other molecular liquids.
在这项工作中，我们研究了实验表面张力测量是否能够替代通常依赖汽化热作为分子液体力场模型拟合实验参考数据的方法，因为前者对量子和自极化修正的敏感度较低。为了验证这一假设，我们开发了必要的拟合协议，以便在 ForceBalance 优化过程中利用表面张力测量来确定修订后的三点和四点水模型 TIP3P-ST 和 TIP4P-ST 的参数。我们发现，在拟合中加入表面张力会导致刚性三点模型，该模型首次重现了水的最大密度温度，但也导致液体过度结构化和传输性质不够准确。刚性四点 TIP4P-ST 模型在广泛的热力学和动力学性质方面具有高度准确性，与最近开发的四点水模型相比性能相似。结果表明，表面张力通常是一种有用的拟合性质，特别是在无法轻易获得自极化修正或核量子修正来修正汽化热的情况下，因为其他分子液体也存在这种情况。
