Along with the thermal and activation stability targeted when constructing USMOF DB, mechanical stability should also be considered for gas storage applications that often involve applying hydrostatic pressure to the structure. From a number of possible measures of mechanical stabilities, such as elastic modulus, shear modulus, or hardness, we used the Voigt-Reuss-Hill average value of bulk elastic modulus (KVRH). We chose KVRH as the representative measure after determining that the bulk modulus and shear modulus (GVRH) show linear correlation with Pearson's r = 0.88 in USMOF DB (see Sec. 2 and Supporting Information Figure ). Due to the high porosity and low density of MOFs, they are relatively soft materials. Although there exist some extreme cases such as the UiO-66 MOF with computed bulk moduli up to 40 GPa 47 , typical experimentally realized MOFs fall into the range of 4-30 GPa. 100 Analyzing the structural features of MOFs with KVRH less than 5 GPa, we note that most are unphysically porous with cell volumes and pore volumes up to 10x that of the more stable (i.e., KVRH > 5 GPa) structures (Supporting Information Figure ). MOFs with such large pore volumes are more prone to structural distortion from hydrostatic compression, leading to pressure-induced amorphization. We thus classify a MOF with KVRH greater than 5 GPa as a "mechanically stable" MOF. From a total of 9,524 MOFs in the USMOF DB with "ultrastable" thermal and activation stability, 1,102 MOFs remain after applying this mechanical stability criterion of KVRH > 5 GPa. Importantly, upon applying this threshold for mechanical stability, the metal diversity within USMOF DB remains relatively unchanged, with notable enrichment in Co (Figure ). This enrichment is due to the high survival rate of Co-containing node N41 and N18 (57.8% and 52.5%, respectively) upon applying the mechanical stability criterion (see Sec. 3c).