Time-Disordered Crystal Structure of AlPO4-5,The Journal of Physical Chemistry C

当前位置： X-MOL 学术 › J. Phys. Chem. C › 论文详情

Our official English website, www.x-mol.net, welcomes your feedback! (Note: you will need to create a separate account there.)

Time-Disordered Crystal Structure of AlPO4-5
The Journal of Physical Chemistry C ( IF 3.3 ) Pub Date : 2017-08-21 00:00:00 , DOI: 10.1021/acs.jpcc.7b06415
D. L Cortie _{1,

2} , B. R. McBride ₁ , N. Narayanan _{1,

2} , N. R. de Souza ₂ , M. Avdeev ₂ , R. A. Mole ₂ , G. J. McIntyre ₂ , G. J. Kearley ₂ , R. Withers ₁ , D. H. Yu ₂ , Y. Liu ₁

Affiliation

Modern ab initio calculations have become increasingly accurate for predicting the symmetry of crystal structures; however, the standard methods usually only determine the 0 K static configuration and therefore misrepresent structures where dynamics play a key role. In this work, we demonstrate a clear experimental example of this phenomenon in the AlPO₄-5 molecular sieve where the average high-symmetry P6cc structure emerges from local dynamics involving corner-sharing tetrahedra. Quasielastic and inelastic neutron scattering experiments were conducted to clarify the thermally activated motions between 1.5 and 300 K. Through comparison with ab initio molecular dynamics, we explain why the theoretically predicted structure is not observed in diffraction experiments. Instead, the results indicate this material is an inorganic analogue of a plastic crystal where thermal dynamics dictate the average symmetry.

中文翻译：

AlPO ₄ -5的无序晶体结构

现代的从头算计算已经越来越准确地用于预测晶体结构的对称性。但是，标准方法通常仅确定0 K静态配置，因此在动态性起关键作用的结构上会出现错误的表象。在这项工作中，我们展示了AlPO ₄ -5分子筛中此现象的清晰实验示例，其中平均高对称性P 6 cc结构是由涉及角共享四面体的局部动力学产生的。准弹性和非弹性中子散射实验以阐明1.5和300 K之间的热活化的运动通过与比较从头分子动力学，我们解释了为什么在衍射实验中没有观察到理论上预测的结构。相反，结果表明该材料是塑料晶体的无机类似物，其中热动力学决定了平均对称性。

更新日期：2017-08-21

点击分享查看原文

点击收藏

阅读更多本刊新发论文本刊介绍/投稿指南