中文摘要：

利用分子力场和分子动力学（MD）的方法研究了Li-蒙脱石的结构构型,层间阳离子的水化行为、水分子的结构特征以及它们的扩散性质.分子力场构型优化结果表明：Li-蒙脱石的层间距、体积和密度与层间水含量有关;MD模拟的动画轨迹显示Li-蒙脱石层间Li＋的位置与层间电荷位置有关.均方根位移和自扩散系数的计算结果表明：层间阳离子、水分子在Li-蒙脱石一、二层水合物中的扩散受到上下粘土片表面的限制,在三层水合物中开始离开粘土层面向其它方向快速扩散.径向分布函数及其结构因子的分析结果表明Li＋在一、二、三层水合物中有不同的水合层;层间水分子的结构特征说明其在蒙脱石层间有水合水分子和自由水分子之分,且它们的比值在一、二和三层水合物中有所不同.

英文摘要：

The structure configuration, hydrated behavior of counterions, structure properties and diffusion features of water molecules in the interlayer of lithium montmorillonite were investigated by molecular force field and molecular dynamics simulation （MD）. The configuration optimization results of molecular force field showed that the layer spacing, density and volume were related to the water content in the interlayer of lithium montmorillonite. The animated trajectory of molecular dynamics simulation demonstrated that the positions of Li＋ ions in the interlayer of lithium montmorillonite were related with interlayer charge sites in clay sheets. The results of mean square displacement （MSD） and self-diffusion coefficients illustrated that the diffusion of counterions and water molecules were restricted to the surface of clay sheets when in one-and two-layer hydrates of lithium montmorillonite. In the three-layer hydrates, the Li＋ ions and water molecules became detached from the surface and began quickly diffused towards the other direction. The analysis results of radial distribution function （RDF） and its structure factor showed that the hydrated shell of Li＋ ions in one-, two-, and three-layer hydrates were different. The structure properties of watermolecules in the interlayer of lithium montmorillonite indicated that water molecules were differentiated with molecules and free water molecules, and the ratio of them differed in one-, two-and three-layer hydrates.