An electronically polarizable force field based on Thole model has been developed for the ionic liquids (ILs). Molecular dynamics simulation studies were then performed on both the polarizable and non-polarizable versions of the model of IL 1-ethyl-3- methylimidazolium nitrate (EMIM⁺/NO₃^-). The current study shows that introducing the electronic polarizability for the polarizable model leads to the quite different structural properties than the non-polarizable model. The ionic packing pattern is found to be strongly altered around NO₃^-, which leads to the different anion-anion center of mass partial radial distribution function. A common feature shared by both models is that they all retain the memory of the crystal structure, even though the simulation performed at 400 K is more than 100 K higher than the melting point (38 ℃). The polarizable model also improves transport properties, which is in better agreement with experiment. The current study shows that polarization effect is important in ILs.

言天英, 研究员, 博士生导师。1992年本科毕业于厦门大学, 2003年获得美国韦恩州立大学博士学位。2003年至2004年期间为美国犹他大学博士后。2004年聘为副教授加入南开大学化学学院; 2010年晋升为研究员, 目前在南开大学材料科学与工程学院。研究方向是理论与计算化学、分子动力学模拟、功能材料设计; 主要开展新能源与材料化学相关体系的理论与计算化学方面的研究。发表SCI收录论文80多篇。