Kuo I-F Will, Mundy Christopher J, Eggimann Becky L, McGrath Matthew J, Siepmann J Ilja, Chen Bin, Vieceli John, Tobias Douglas J
Computational Chemical Biology, Lawrence Livermore National Laboratory, P.O. Box 808, Livermore, California 94551, USA.
J Phys Chem B. 2006 Mar 2;110(8):3738-46. doi: 10.1021/jp056330t.
This research addresses a comprehensive particle-based simulation study of the structural, dynamic, and electronic properties of the liquid-vapor interface of water utilizing both ab initio (based on density functional theory) and empirical (fixed charge and polarizable) models. Numerous properties such as interfacial width, hydrogen bond populations, dipole moments, and correlation times will be characterized with identical schemes to draw useful conclusions on the strengths and weakness of the proposed models for interfacial water. Our findings indicate that all models considered in this study yield similar results for the radial distribution functions, hydrogen bond populations, and orientational relaxation times. Significant differences in the models appear when examining both the dipole moments and surface relaxation near the aqueous liquid-vapor interface. Here, the ab initio interaction potential predicts a significant decrease in the molecular dipole moment and expansion in the oxygen-oxygen distance as one approaches the interface in accordance with recent experiments. All classical polarizable interaction potentials show a less dramatic drop in the molecular dipole moment, and all empirical interaction potentials studied yield an oxygen-oxygen contraction as the interface is approached.
本研究利用从头算（基于密度泛函理论）和经验（固定电荷和可极化）模型，对水的液-气界面的结构、动力学和电子性质进行了全面的基于粒子的模拟研究。诸如界面宽度、氢键数量、偶极矩和相关时间等众多性质将采用相同的方案进行表征，以便就所提出的界面水模型的优缺点得出有用的结论。我们的研究结果表明，本研究中考虑的所有模型在径向分布函数、氢键数量和取向弛豫时间方面都产生了相似的结果。在研究偶极矩和水的液-气界面附近的表面弛豫时，模型之间出现了显著差异。在这里，从头算相互作用势预测，随着接近界面，分子偶极矩会显著降低，氧-氧距离会增大，这与最近的实验结果一致。所有经典的可极化相互作用势显示分子偶极矩的下降幅度较小，并且所研究的所有经验相互作用势在接近界面时都会导致氧-氧距离收缩。
