不同势能模型下的水分子动力学性质  

Study on Dynamic Properties of Water Molecular under Different Potential Models

作　　者：俞联梦 YU Lian-meng(Lijiang Teachers College,Lijiang 674199,China)

机构地区：[1]丽江师范高等专科学校,云南丽江674199

出　　处：《工业技术创新》2020年第5期85-89,共5页Industrial Technology Innovation

基　　金：教育后勤疫情防控专项课题(课题编号:ZXYBKT202022)。

摘　　要：采用分子动力学方法,对SPC、SPCE、TIP3P、TIP4P、TIP5P五种势能模型下水分子的热力学性质、径向分布函数、自扩散系数进行计算,优选最适合于水分子动力学性质研究的势能模型。研究发现:1)采用SPCE模型通过模拟得到的内能、汽化焓最为准确,其他模型受到了模型固有性质和系综(大量宏观上完全相同的体系的抽象集合)的影响,模拟结果不甚理想;2)采用SPCE、TIP4P、TIP5P模型可以较好地反映水分子短程有序、长程无序的微观结构;3)采用SPCE模型通过模拟得到的自扩散系数相对误差仅为0.39%,远好于其他模型。结果表明,SPCE模型能够较真实地反映水分子的热力学性质、微观结构和自扩散特性等动力学性质。The thermodynamic properties,radial distribution function and self-diffusion coefficient of water molecules in 5 potential models,i.e.SPC,SPCE,TIP3P,TIP4P and TIP5P are calculated by the molecular dynamics method,and the most suitable potential model for the water molecular dynamics is selected.The results show that:1) the internal energy and enthalpy of vaporization simulated by the SPCE model are the most accurate,and other models are affected by the inherent properties and ensemble (abstract set of a large number of macroscopically identical systems) of models,so their simulation results are not ideal;2) the SPCE,TIP4P,TIP5P models can better reflect the short-range ordered and long-range disordered microstructure of water molecules;3) the relative error of self-diffusion coefficient simulated by the SPCE model is only 0.39%,much better than other models.The results show that the SPCE model can better reflect the molecular dynamic properties including the thermodynamic properties,microstructure and self-diffusion characteristics of water molecules.

关 键 词：水分子 势能模型 动力学 径向分布函数 自扩散系数 

分 类 号：O645[理学—物理化学]