Abstract In this paper, a two-dimensional lattice-gas model is applied to study the stability and lattice distortion of sI clathrate hydrates of ethylene. Two levels of approximation are considered for the lateral interactions between the adsorbed molecules. By using Monte Carlo simulations, adsorption isotherm (coverage of the cavities as a function of the chemical potential), degree of deformation of the sI structure, and free energy of the adsorbed phase are obtained. A direct relationship between cell distortion and cell occupancy is observed. In addition, the minimum distortion coincides with the minimum value of the free energy. Accordingly, the stability phase diagram can be calculated from the values of the chemical potential at the minimum deformation. The obtained results indicate that the most stable condition of the system occurs for values of the cavity density ranging between 0.35 and 0.4. Finally, MC results are compared with data from experiments and more complex simulations.

中文翻译：

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乙烯的 sI 笼形水合物的晶格气体蒙特卡罗研究：稳定性分析和电池畸变

摘要 本文应用二维晶格-气体模型研究了乙烯的sI包合物水合物的稳定性和晶格畸变。对于吸附分子之间的横向相互作用，考虑了两个近似水平。通过使用蒙特卡罗模拟，获得吸附等温线（空腔覆盖率作为化学势的函数）、sI 结构的变形程度和吸附相的自由能。观察到单元失真和单元占用之间的直接关系。此外，最小畸变与自由能的最小值一致。因此，稳定相图可以从最小变形处的化学势值计算出来。获得的结果表明，系统最稳定的状态出现在腔密度值范围在 0.35 和 0.4 之间。最后，将 MC 结果与来自实验和更复杂模拟的数据进行比较。