We observed that certain building blocks appeared frequently in the top 20 MOFs ranked by CH4 working capacity in the mechanically stable subset of the USMOF DB. Specifically, inorganic node 41 (N41), extracted from CSD refcode: KOZSID in CoRE MOF 2019, appears 11 times in the top 20 MOFs, all exhibiting CH4 working capacities greater than 790 cm 3 /g (Supporting Information Table ). Although N41 occurs frequently in the USMOF DB, being present in 16.2% (178 out of 1,102) of MOFs, its appearance in the top 20 MOFs is still enriched with respect to its presence in the mechanically stable subset. Chemically, N41 is a Co-based porphyrinic node, the rigid nature of which 103,104 allows the structures to have high mechanical stability, leading to its presence in combination with a number of nets and other linkers in the mechanically stable USMOF DB subset. This finding also aligns with previous research where N41 was frequently observed near the Pareto front of an optimal trade-off between mechanical stability and CH4 working capacity . We nevertheless note that the original MOF in CoRE MOF 2019 (CSD refcode: KOZSID) from which N41 was extracted has a rather low CH4 working capacity of only 12.32 cm 3 /g (Figure ). This unexpected discrepancy in CH4 adsorption arises from the diversity of topologies present in the mechanically stable subset of the USMOF DB, which in turn results in distinct connectivity (Supporting Information Figure ). This difference leads to larger variation in pore volumes, which have high importance for predicting the working capacity, when compared with MOFs containing the same node or edge in the mechanically stable subset of the USMOF DB and CoRE MOF 2019 (Supporting Information Figure ). Edge 13 (E13, from CSD refcode: UVAHIK) frequently appears in MOFs with high CH4 working capacity as well (i.e., 10 times in the top 20 MOFs). It contains 3 benzene rings, making it one of the longest edges (12.7 Å) in our organic edge building block set. This allows the structures to have larger pore volumes and higher working capacities. Although there are longer edge building blocks than E13, they do not appear frequently in the mechanically stable set of USMOF DB because they are more susceptible to instability upon application of hydrostatic pressure, resulting in lower mechanical stability. Next, we repeated our analysis on the MOF components with high occurrence in the top 20 MOFs in the mechanically stable subset of the USMOF DB for CO2 working capacity (Supporting Information Table ). In comparison to CH4, no single inorganic node dominates as consistently, with node 61 (N61, CSD refcode: OJICUG, 6 times) and node 29 (N29, CSD refcode: TAGTUT, 5 times) each occurring about 25% of the time. Notably, N61 is consistently selected in structures that include other inorganic or organic nodes to form either a 2 inorganic node-1 edge or a 1 inorganic node-1 organic node-1 edge configuration (Figure ). All 11 MOFs containing these nodes have CO2 working capacities greater than 580 cm 3 (STP)/g framework. The original CO2 working capacities of the CoRE MOF 2019 MOFs, from which N61 and N29 were taken, were 340.3 cm 3 /g and 295.9 cm 3 /g, respectively. Although these values are lower than the working capacities in USMOF DB, they still exceed one standard deviation (127.7 cm 3 /g) above the average value of CO2 working capacity (average: 133.6 cm 3 /g + 1 std. dev. is 261.3 cm 3 /g) in CoRE MOF 2019. The less dramatic difference for CO2 compared to the case of CH4 is expected because ML model feature importance indicates CO2 working capacity depends on both geometric features and the chemical identity of nodes (see Sec. 3b). Thus, recombining the nodes with alternate linkers and on new nets should result in a wide range of geometric features that could alter working capacities, but it has a smaller impact on CO2 working capacity compared to CH4.