应用L-J(12/6)势能模型对Fe^(2+)水化作用的分子动力学模拟(英文)

Molecular Dynamics Simulation of Fe^(2+) Hydration Process using the L-J(12/6) Interaction Potential Model

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=0.180kcal·mol-1和σIW=0.2885nm。然后在298.15K和573K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+水化结构和动力学性质的影响。

This study initially obtained the two parameters εw=0.180 kcal .mol^-1 and σIW-=0.288 5 nm of the Lennard-Jones （12/6） potential for Fe^2＋-waters interaction. Then, the L-J （12/6） potential with the two parameters obtained was employed to carry out MD simulation of Fe^2＋ 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 Fe^2＋ hydration in the first and second hydration shells agree well with these properties from experiments, as well as other computer simulations in which different Fe^2＋-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 Fe^2＋ hydration structure and dynamics properties.