Slow dynamics attributed to topological frustration

在拓扑受挫理论概念的基础上，通过分子动力学模拟和同步辐射X射线衍射实验研究了压力诱导非晶化的物理机制。目标样品为分子晶体四碘化锡，它被认为是一种压力诱导玻璃成形剂。解释了非晶化的真正机制是由于分子解离。在已有结果的基础上，讨论了拓扑受挫对低压区局部结构和宏观热力学特征的影响，并从分子间相互作用的角度对这些结果进行了理论上的重新检验。后者的一个可能的修正来源是一个短程八极-八极相互作用，这可能是高压下的主要贡献。最后，从拓扑受挫的角度解释了SnI_4中的分子解离现象。

On the basis of a new theoretical concept of topological frustration physical mechanism of pressure-induced amorphization was investigated conducting both molecular dynamics simulations and synchrotron x-ray diffraction experiments. A molecular crystal tin tetraiodide was chosen as a target sample, which has been known as a pressure-induced glass former. The very mechanism of the amorphization was elucidated to be due to molecular dissociation. Appearance of the effects of topological frustration on the local structure as well as the macroscopic thermodynamic features in the low-pressure regime is discussed on the basis of the results hitherto obtained, which were theoretically re-examined focusing on the intermolecular interaction. A possible source of modification of the latter is a short-ranged octupole-octupole interaction, which may be a dominant contribution under high pressures. Finally, the phenomena of molecular dissociation occurred in SnI_4 is interpreted in terms of topological frustration.