论文标题
绿绿色的水分子的方向和动力学
Orientation and dynamics of water molecules in beryl
论文作者
论文摘要
$^1 $ h和$^2 $ h核磁共振光谱研究对绿绿色单晶的正常和重水分子的单个分子的行为进行了研究。根据光谱的温度依赖性，我们推断出嵌入在绿色空隙中的I型水分子与文献中所建立的观点的定向截然不同。也就是说，与早期的假设相反，其H-H线偏离了六角形轴约18 $^\ circ $。我们建议这是由于分子附着在氧原子上，形成氢键形成绿绿色的结构空隙。我们的分析表明，分子执行两种运动类型：（i）围绕氢键轴的快速库，以及（ii）在绿色绿色空隙中的十二个可能的结合位点中频繁的定向跳跃。从简单的热力学模型中评估了库动作的频率，从而提供了与前面报道的光学实验中库频率的良好定量一致性。
Behavior of individual molecules of normal and heavy water in beryl single crystals was studied by $^1$H and $^2$H nuclear magnetic resonance spectroscopy. From temperature dependences of the spectra we deduce that type-I water molecules embedded in the beryl voids are oriented quite differently from the view established in the literature. Namely, contrary to earlier assumptions, their H-H lines deviate by about 18$^\circ$ from the hexagonal axis. We suggest that this is due to the molecules attaching to the oxygen atoms forming the beryl structural voids by a hydrogen bond. Our analysis shows that the molecules perform two types of movement: (i) rapid librations around the axis of the hydrogen bond, and (ii) less frequent orientational jumps among the twelve possible binding sites in the beryl voids. The frequencies of the librational motions are evaluated from a simple thermodynamic model, providing a good quantitative agreement with the frequencies of librations from optical experiments reported earlier.
