Abstract Structure-H gas hydrate is recognized by its hexagonal symmetry and anisotropy. The available structure-mechanical properties relations of this hydrate from an atomistic scale are scarce. This work presents the main mechanical properties of sH hydrate addressing its structural anisotropy based on ab initio atomic simulations. The empty metastable and filled sH hydrates of neohexane and different help gases are simulated to establish their mechanical and anisotropic characteristics. Guest molecules increase the stiffness and rigidity of sH hydrate, and they define its anisotropy. The anisotropy of sH hydrate was reflected in its high moduli values along the c-axis as compared to the a-axis. Analyzing sH hydrate response to applied triaxial stress reveals its maximum tensile strength. The hydrogen and the covalent O-H bonds were found to behave in an opposite manner under applied stress. This work contributes to the fundamental understanding and potential technological applications of this less known gas hydrate.

中文翻译：

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从第一性原理看结构-H (sH) 气体水合物的弹性特性和各向异性行为

摘要 结构-H型天然气水合物因其六边形对称性和各向异性而被公认。从原子尺度来看，这种水合物的可用结构-机械性质关系很少。这项工作基于 ab initio 原子模拟，介绍了 sH 水合物的主要机械性能，解决了其结构各向异性问题。模拟空的亚稳态和填充的新己烷和不同辅助气体的 sH 水合物，以确定它们的机械和各向异性特性。客体分子增加了 sH 水合物的刚度和刚性，并定义了其各向异性。sH 水合物的各向异性反映在其沿 c 轴的高模量值与 a 轴相比。分析 sH 水合物对施加的三轴应力的响应揭示了其最大拉伸强度。发现氢和共价 OH 键在施加应力下以相反的方式表现。这项工作有助于对这种鲜为人知的天然气水合物的基本理解和潜在的技术应用。