“…Clearly, the first and second compressive deformation stages in Figure correspond to distortions of polyhedral water cages in methane hydrates (Figure a–c,e,f,i,j) under weak electric fields. This compression-induced distortion of polyhedral water cages in molecular structures differs from the tension-induced ones, resulting from the difference in the distinct relative angles of tetrahedral hydrogen bonds making to the loading direction. , Such molecular structural changes can well rationalize the asymmetry of tension–compression in mechanical properties of methane hydrates. At high compressive strains as shown in Figure c,d,g,h,k,l, once localized polyhedral water cages collapse, strain-induced collapses of polyhedral water cages propagate into other areas of methane hydrates, thereby resulting in the dissociation of methane hydrates.…”