Faculty of Science, Charles University Prague, Albertov 6, Prague, 128 43, Czech Republic.
J Phys Chem A. 2011 Jun 16;115(23):5973-82. doi: 10.1021/jp110391q. Epub 2011 Mar 31.
We use molecular dynamics simulations to determine the melting point of ice I(h) for the polarizable POL3 water force field (Dang, L. X. J. Chem. Phys.1992, 97, 2659). Simulations are performed on a slab of ice I(h) with two free surfaces at several different temperatures. The analysis of the time evolution of the total energy in the course of the simulations at the set of temperatures yields the melting point of the POL3 model to be T(m) = 180 ± 10 K. Moreover, the results of the simulations show that the degree of hydrogen-bond disorder occurring in the bulk of POL3 ice is larger (at the corresponding degree of undercooling) than in ice modeled by nonpolarizable water models. These results demonstrate that the POL3 water force field is rather a poor model for studying ice and ice-liquid or ice-vapor interfaces. While a number of polarizable water models have been developed over the past years, little is known about their performance in simulations of supercooled water and ice. This study thus highlights the need for testing of the existing polarizable water models over a broad range of temperatures, pressures, and phases, and developing a new polarizable water force field, reliable over larger areas of the phase diagram.
我们使用分子动力学模拟来确定可极化 POL3 水力场（Dang，L. X. J. Chem. Phys.1992, 97, 2659）中冰 Ih 的熔点。在几个不同的温度下，对具有两个自由表面的冰 Ih 薄片进行模拟。在设定的温度下，通过对模拟过程中总能量的时间演化进行分析，得出 POL3 模型的熔点为 T(m) = 180 ± 10 K。此外，模拟结果表明，在 POL3 冰的体相发生的氢键无序程度（在相应的过冷度下）比非极化水分子模型建模的冰更大。这些结果表明，POL3 水力场在研究冰、冰-液或冰-汽界面方面并不是一个很好的模型。虽然在过去几年中已经开发了许多可极化水分子模型，但对于它们在过冷水和冰的模拟中的性能知之甚少。因此，这项研究强调了需要在广泛的温度、压力和相范围内对现有可极化水分子模型进行测试，并开发一个新的、在相图更大区域内可靠的可极化水分子力场。
