Jiang Hao, Moultos Othonas A, Economou Ioannis G, Panagiotopoulos Athanassios Z
Department of Chemical and Biological Engineering, Princeton University , Princeton, New Jersey 08544, United States.
Chemical Engineering Program, Texas A&M University at Qatar , P.O. Box 23874, Doha, Qatar.
J Phys Chem B. 2016 Dec 8;120(48):12358-12370. doi: 10.1021/acs.jpcb.6b08205. Epub 2016 Nov 22.
A polarizable intermolecular potential model with short-range directional hydrogen-bonding interactions was developed for water. The model has a rigid geometry, with bond lengths and angles set to experimental gas-phase values. Dispersion interactions are represented by the Buckingham potential assigned to the oxygen atom, whereas electrostatic interactions are modeled by Gaussian charges. Polarization is handled by a Drude oscillator site, using a negative Gaussian charge attached to the oxygen atom by a harmonic spring. An explicit hydrogen-bonding term is included in the model to account for the effects of charge transfer. The model parameters were optimized to density, configurational energy, pair correlation function, and the dielectric constant of water under ambient conditions, as well as the minimum gas-phase dimer energy. Molecular dynamics and Gibbs ensemble Monte Carlo simulations were performed to evaluate the new model with respect to the thermodynamic and transport properties over a wide range of temperature and pressure conditions. Good agreement between model predictions and experimental data was found for most of the properties studied. The new model yields better performance relative to the majority of existing models and outperforms the BK3 model, which is one of the best polarizable models, for vapor-liquid equilibrium properties, whereas the new model is not better than the BK3 model for representation of other properties. The model can be efficiently simulated with the thermalized Drude oscillator algorithm, resulting in computational costs only 3 times higher than those of the nonpolarizable TIP4P/2005 model, whereas having significantly improved properties. Because it involves only a single Drude oscillator site, the new model is significantly faster than polarizable models with multiple sites. With the explicit inclusion of hydrogen-bond interactions, the model may provide a better description of the phase behavior of aqueous mixtures.
针对水开发了一种具有短程定向氢键相互作用的可极化分子间势模型。该模型具有刚性几何结构，键长和键角设定为实验气相值。色散相互作用由赋予氧原子的Buckingham势表示，而静电相互作用则通过高斯电荷建模。极化由Drude振子位点处理，使用通过谐波弹簧连接到氧原子的负高斯电荷。模型中包含一个明确的氢键项以考虑电荷转移的影响。模型参数针对环境条件下水的密度、构型能量、对关联函数和介电常数以及最小气相二聚体能量进行了优化。进行了分子动力学和Gibbs系综蒙特卡罗模拟，以评估新模型在广泛温度和压力条件下的热力学和传输性质。对于大多数研究的性质，发现模型预测与实验数据之间有良好的一致性。相对于大多数现有模型，新模型具有更好的性能，并且在气液平衡性质方面优于BK3模型（最佳可极化模型之一），而在表示其他性质方面新模型并不比BK3模型更好。该模型可以使用热化的Drude振子算法进行有效模拟，计算成本仅比不可极化的TIP4P/2005模型高3倍，同时性能有显著提高。由于它只涉及单个Drude振子位点，新模型比具有多个位点的可极化模型要快得多。通过明确包含氢键相互作用，该模型可能对水性混合物的相行为提供更好的描述。
