Methane Occupancy Control Mechanics and Failure of sII CH ₄ ‐THF Hydrates

CH ₄ ‐tetrahydrofuran (THF)binary hydrates serve as an ideal structural surrogate model for investigating the mechanical stability of gas hydrates under external loading. Molecular dynamics simulations were performed to investigate how CH ₄ occupancy in small 5 ¹² cages affects tensile properties and failure mechanisms of CH ₄ ‐THF hydrates, with THF fully occupying large 5 ¹² 6 ⁴ cages. Increasing CH ₄ occupancy from 0% to 100% enhances ultimate tensile stress from 0.70 to 0.94 GPa, ultimate strain from 0.103 to 0.126, and Young’s modulus from 7.1 to 8.8 GPa. This strengthening arises from guest‐induced van der Waals support and steric confinement, which reinforce the water framework and suppress lateral deformation. Microscopically, low CH ₄ occupancy promotes stress concentration around vacant cages, causing early shear localization and local amorphization. In contrast, high CH ₄ occupancy delays framework collapse and promotes the accumulation of metastable unconventional cages within shear bands, dissipating deformation energy and buffering crack propagation. These findings provide atomistic guidance for evaluating the intrinsic robustness of binary hydrates in solid natural gas (SNG) storage and transportation.