high performance with a deliverable capacity larger than 150 (v STP/v). It is interesting that even for MOFs which have different chemical compositions (unlike zeolites), our method of identifying similar pore shapes illustrates the importance of pore geometry, and hence, of our methodology to quantify similarity for these types of materials.

We can also use our approach to study the topological diversity of the top-performing materials for methane storage. Bathia and Myers[@bha061] analyzed a small number of porous materials and concluded that top-performing materials should all have very similar heats of adsorption for given loading and de-charging pressures. Their work has had significant impact, as it provides a straightforward experimental recipe for optimizing the deliverable capacity of a material.[@mas141] I.e., if all top-performing materials shared a similar heat of adsorption, having a heat of adsorption similar to this value was a necessary condition for all good performing materials. Given this impact it is surprising that the conclusion of Bathia and Myers stands in sharp contrast with observations of Simon [*et al*]{}.[@sim141] Simon [*et al.*]{} computed the deliverable capacity for over 200,000 zeolite structures, and their data (Figure \[QadGroups\]a) provide no evidence for a single optimal heat of adsorption, pointing to 