Structure of the interlayer in normal 11 Å tobermorite from an ab initio study
Structure of the interlayer in normal 11 Å tobermorite from an ab initio study
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从头开始研究的正常 11 Å 雪硅石夹层结构
DOI：
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发表时间：
2009
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通讯作者：
S. Churakov
中科院分区：
文献类型：
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作者：
S. Churakov
基于从头算分子动力学模拟方法，分析了普通11A托贝莫来石中间层水分子的结构位置和动力学。计算得到的托贝莫来石结构参数与X射线衍射和EXAFS测量结果吻合较好。模拟提供了关于水分子形成的氢键网络结构、OH基团和层间钙离子配位的详细信息。未与层间钙离子键合的W1、W2和W3位的结构位置与异常11A托勃莫来石中的相应位相似。这些分子在其平衡位置经历缓慢的旋转运动。形成层间钙离子配位壳层的H2O分子具有固定的取向，这种取向受到与邻近氧位的强氢键的制约。根据计算的振动态密度，解释了天然11A托勃莫来石的红外光谱。
The structural positions and dynamics of water molecules in the interlayer of normal 11 A tobermorite were analyzed based on ab initio molecular dynamics simulations. The calculated structural parameters of the tobermorite building blocks are in good agreement with the results of X-ray diffraction and EXAFS measurements. The simulations provide detailed information on the structure of the hydrogen bonding network formed by water molecules, the OH groups, and the coordination of interlayer Ca ions. Structural position of W1, W2 and W3 sites non-bonded to the interlayer Ca ions were found to be similar to the corresponding sites in the anomalous 11 A tobermorite. These molecules undergo a slow rotational motion at the position of their equilibria. The H 2 O molecules forming coordination shell of interlayer Ca ions have a fixed orientation that is constrained by strong hydrogen bonds to neighbouring oxygen sites. The IR spectrum of natural 11 A tobermorite was interpreted based on the calculated vibrational density of state.