Some other metals that occur somewhat frequently in our set include Zr ( ), Ni (13), and Ti (11), To develop a more holistic understanding of the MOFs in our set, we featurized the structures with Zeo++ 59 and analyzed their geometric properties. The average surface area is 1302 m 2 /g with about 25 structures with high surface areas greater than 2000 m 2 /g, which would be expected to be most beneficial for high-capacity adsorption applications. Based on geometric features, 11 MOFs have sub-4 Å diameter pores that Zeo++ 59 measured as having zero surface area due to the comparable size of the pore to the nitrogen probe size. The largest observed pore size is 27 Å, with an overall mean of 8.6 Å (Figure ). The pore volumes vary widely from 4.4 to 10,303 Å 3 with a mean of 742 Å 3 . Although it may be counterintuitive to investigate structures with nominal pore sizes that appear too restrictive for C2 separation applications, small pore sizes may combine with framework flexibility to allow MOFs to selectively accommodate one adsorbate over another. The pore volume and pore limiting diameter also show log-normal distributions with a few large-pore outliers, such as MIL-100(Fe), NIIC-20, and PCN-224(Zr) (Figure ). We can infer from the broad distributions in the geometric features of the K-C2 dataset that a wide range of MOF geometries have been explored for C2 adsorption.