应用L-J(12/6)势能模型对Fe2+水化作用的分子动力学模拟

摘要

本文首先优化出Fe2+和水分子相互作用的Lennard-Jones(12/6)势能模型中的2个参数:εIW=0.180 kcal·mol-1和σIW=0.2885nm.然后在298.15 K和573 K温度条件下,用这个势能模型去运行Fe2+极稀水溶液系统的分子动力学模拟.模拟的结果显示,Fe2+的第一和第二水化壳层的结构和动力学性质与实验的,以及其他势能模型模拟出的结果一致.模拟的同时获得了关于RWK2水分子模型内部结构变化的新信息.此外,模拟揭示了温度变化对Fe2+化结构和动力学性质的影响.%This study initially obtained the two parameters εIW=0.180 kcal·mol-1 and σIW=0.288 5 nm of the Lennard-Jones(12/6)potential for Fe2+-waters interaction.Then,the L-J(12/6)potential with the two parameters obtained was employed to carry out MD simulation of Fe2+ hydration process for a dilute aqueous solution system at 298.15 K and 573 K,respectively.The results show that structural and dynamics properties of Fe2+ hydration in the first and second hydration shells agree well with these properties from experiments,as well as other computer simulations in which different Fe2+- waters interaction potentials were employed.Besides,the results give some new insights into RWK2 water intramolecular geometry.In addition,it is also indicated that increasing temperature has a certain impact on the Fe2+ hydration structure and dynamics properties.