We next compared the computed working capacities of CO2 and CH4 for the "ultrastable" subset of USMOF DB to those of the experimental CoRE MOF 2019 DB . We used the adsorption data calculated by Moosavi et al. for the latter, where they successfully calculated adsorption properties of 9,525 MOFs. We first classify the MOFs into three groups according to their CO2:CH4 working capacity ratios: i) high, where the ratio is greater than 1.1, ii) low, where the ratio is less than 0.9, and iii) intermediate, where ratio is between 0.9 and 1.1. While most of the MOFs from the CoRE MOF 2019 DB (89.4%) have a high ratio (i.e., greater than 1.1), only 27.5% of MOFs in the mechanically stable, "ultrastable" subset of the USMOF DB fall into this category (Supporting Information Table ). We also note that the working capacity ranges are different between the two databases. Specifically, the majority of MOFs (92.7%) in CoRE MOF 2019 have a CH4 working capacity below 200 cm 3 (STP)/g framework, while very few MOFs (3%) in USMOF DB have a working capacity below that threshold. A similar trend is observed for CO2 working capacity, as 77.8% of MOFs in CoRE MOF 2019 and only 7 MOFs (0.6%) in the mechanically "ultrastable" subset of the USMOF DB have a working capacity below 200 cm 3 (STP)/g framework for CO2. Overall, USMOF DB contains some MOFs with exceptionally high CH4 working capacity, while CoRE MOF 2019 predominantly contains MOFs with preferentially high CO2 working capacity, albeit with lower working capacity overall than the topperforming MOFs in USMOF DB. Thus, the hypothetical MOFs in USMOF DB can be candidate materials with higher working capacities than MOFs in the CoRE MOF 2019 DB for both CH4 and CO2, but many exhibit higher CH4 working capacities than CO2.