论文标题
朝着CSCL水溶液的正确显微镜结构进行比较
Towards the correct microscopic structure of aqueous CsCl solutions with a comparison of classical interatomic potential models
论文作者
论文摘要
通过经典分子动力学模拟（MD）以三种盐浓度（1.5、7.5和15 mol％）研究了CSCL溶液水溶液的结构。基于12-6 Lennard-Jones模型的30个原子势集，用于非极化水溶剂分子的参数化和测试。将一些基本特性（例如密度，静电介电常数和自扩散系数）与力场（FF）预测的自我扩散系数与可用的实验数据进行了比较。模拟粒子构型用于计算部分径向分布函数（PRDF）以及中子和X射线总散射结构因子（TSSF）。将TSSF与文献的实验数据进行了比较，以找到正确描述结构的最佳FF模型。已经发现，尽管三十个模型中的几个模型在测试中失败了，但某些模型与测量数据兼容。确定与实验一致的结构参数的值（例如离子距离，离子周围的平均水分子数，平均数量，平均数量和阴离子启动接触离子对之间的距离，水 - 水氢键）。结果表明，除了接触离子对数量太高的模型外，该数字太低的模型也无法再现实验数据。
The structure of aqueous CsCl solutions was investigated by classical molecular dynamics simulations (MD) at three salt concentrations (1.5, 7.5, and 15 mol %). Thirty interatomic potential sets, based on the 12-6 Lennard-Jones model, parametrized for non-polarizable water solvent molecules were collected and tested. Some basic properties, such as density, static dielectric constant, and self-diffusion coefficients, predicted by the force fields (FF), were compared with available experimental data. The simulated particle configurations were used to calculate the partial radial distribution functions (PRDF) and the neutron and X-ray total scattering structure factors (TSSF). The TSSFs were compared with experimental data from the literature, to find the best FF models, which describe the structure correctly. It was found that, though several of the thirty models failed in the tests, some models are compatible with the measured data. Values of the structural parameters consistent with the experiments were determined (such as water-ion distances, the average number of water molecules around the ions, average number, and distance between anion-cation contact ion pairs, water-water hydrogen bonds). It was shown, that in addition to models in which the number of contact ion pairs is too high, models in which this number is too low are also unable to reproduce the experimental data.
