水分子团簇分子力场方法的比较研究

采用传统水分子力场模型(SPC, TIPnP(n=3-5))和极化模型(POL3, AMOEBA, SPC-FQ, TIP4P-FQ)对水分子二聚体团簇性质进行了比较和研究. 以从头计算和实验数据为依据, 分析水分子在外场作用下体系的静电极化, 电荷转移和分子结构变化. 通过水分子二聚体结合能和各分解能量项评价极化静电势能在双分子结合能中的地位和作用, 以及各水分子力场的适用性. 通过水分子团簇多体相互作用能的计算,展示不同极化水分子力场定量计算极化能量的实际能力. 通过对力场模型结果的对比和分析, 为进一步发展极化力场模型, 并应用到其他体系提供借鉴和依据.

A Comparative Study of Water Clusters by Classical and Polarizable Water Models

Several classical water models (SPC,TIPnP (n=3-5)) and polarizable water models (POL3,DANG,AMOEBA,SPC-FQ,TIP4P-FQ),combining the results of ab initio methods were employed to study the properties of water clusters,such as structures,dipoles,induced dipoles,charge transfer,polarized energies,many-body energies and binding energies,and were evaluated against the related literature works. Whether the polarized effect could be neglected in the modelng of water clusters,it was judged by the total potential and the decomposed energy terms. All in all,the polarizable water models,especially the induced multiple model (AMOEBA),do better job than classical fixed charge models. Fluctuating charge and four sites model are more realistic to be applied to the biological sytems in consideration of the balance of efficiency and accuracy. The comparable studies of this paper provide a reference for developing the polarized models and applying them to other systems.