Proton disorder and elasticity of hexagonal ice and gas hydrates
Proton disorder and elasticity of hexagonal ice and gas hydrates
复制标题
DOI：
10.1007/s00894-018-3919-x
复制
发表时间：
2019-01
影响因子：
2.2
通讯作者：
S. V. Gudkovskikh;M. Kirov
中科院分区：
文献类型：
--
作者：
S. V. Gudkovskikh;M. Kirov
这项工作是专门的六方冰Ih和气体水合物框架SI，SII和SH的机械性能的研究，考虑到无序的氢原子（质子）的位置。本文强调了弹性能在评价质子组态相对能量中的重要作用。在TINKER软件包的帮助下，使用AMOEBA极化力场进行计算。计算了弹性常数、弹性模量和各向异性指数。结果表明，所有的天然气水合物框架是非常各向同性的，由于它们的笼状结构。据确定，冰Ih的各向异性较高的原因之一是存在大量的高度对称的质子配置。本文的目的是克服从头算方法和力场方法在预测低温下冰结构质子组态的相对稳定性时存在的明显矛盾。另一个目的是评估质子无序对冰和天然气水合物结构弹性性质的影响。
This work is devoted to the study of the mechanical properties of hexagonal ice Ih and gas hydrate frameworks sI, sII and sH, taking into account the disorder in the positions of the hydrogen atoms (protons). The article emphasizes the critical role of the elastic energy for the evaluation of the relative energy of the proton configurations. The calculations are performed with the help of the TINKER package using the AMOEBA polarizable force field. The elastic constants, elastic modulus, and anisotropy indices are calculated. It is shown that all gas hydrate frameworks are very isotropic due to their cage-like structure. It was established that one of the reasons for the higher anisotropy of ice Ih is the presence of a large number of highly symmetric proton configurations. The purpose of the article is to overcome the apparent contradiction between the ab initio and force field methods in predicting the relative stability of the proton configurations of ice structures at low temperature. The other purpose is to evaluate the effect of proton disorder on the elastic properties of ice and gas hydrate structures.