Now we analyze the building blocks (i.e., edges and nodes) and their connectivity (i.e., nets) to identify their relationship with the adsorption preferences of CO2 and CH4 for MOFs in the USMOF DB. We first investigate the edges, examining whether their lengths are correlated with the adsorption preferences of gas species. Our preceding analysis revealed distinct trends within the USMOF DB, with MOFs exhibiting high CH4 working capacity demonstrating longer edge lengths, while no strong correlation was observed between CO2 working capacity and edge length. Now, we observe a notable difference in average edge length between MOFs with CO2:CH4 ratios below 0.9 (10.03 ± 2.82 Å) and those above 1.1 (6.93 ± 2.02 Å,), indicating that edge length may serve as a useful design knob for enhancing CH4 adsorption preference over CO2 (Figure ). Despite the smaller standard deviation for the average length in the high-ratio case, longer edges serve as a better tool for suggesting what the MOF working capacity ratio will be. That is, most of the MOFs (87.5%) with longer edges (> 11 Å) have a low CO2:CH4 ratio, whereas only a slight majority (58.7%) of MOFs with shorter edges (< 7 Å) exhibit a high ratio. Distinct building block configurations (i.e., 1inor-1org-1edge) contribute to this trend: large-pore MOFs that feature longer linkers combined with organic nodes give rise to the lowest CO2:CH4 ratios, while a short linker combined with other components will not necessarily lead to smaller-pore MOFs. We also considered the connectivity net as another factor influencing adsorption preferences, which is particularly necessary because the distribution of connectivity nets observed between the mechanically stable USMOF and CoRE MOF 2019 databases differs (Supporting Information Figure ). Notably, MOFs characterized by topologies that give rise to small gravimetric pore volume (GPOV) and large volumetric surface areas (VSA), such as wiv and ibd, exhibit a preferentially high working capacity for CO2 over CH4 in the USMOF DB and the opposite is true for topologies such as myd and ssa (Supporting Information Figure ). For example, edge E8 (8.6 Å) on an ibd connectivity net appears in 30% of the top 20 MOFs with the highest CO2 working capacity in the mechanically stable subset of USMOF DB (Supporting Information Table ). Therefore, shorter edges with connectivity nets that result in small pore volume and large surface area can be expected to lead to higher CO2 working capacity over CH4, but many of the USMOF DB MOFs have the converse features that instead give rise to higher CH4 working capacity.