At this juncture, we mention the limitations of this work. First, often cages are found to be flexible as opposed to rigid as we took the cages here. In reality, we showed that cages occupy a region in latent space, not a point. Second, as we considered only a single cage molecule in isolation, the latent cage space includes only the notion of intrinsic void space, as opposed to the extrinsic void space that can arise from how the cages pack together to form the bulk solid. In fact, assembly of porous cage molecules to form a bulk solid can be sensitive to small changes in the cage molecule. Depending on the outer surface chemistry and geometry of the molecule, the assembly/packing of porous organic cage molecules can be such that the intrinsic pores in the bulk solid are isolated! 4 For this reason, the simulated Xe/Kr selectivities in the isolated cage molecules in Fig. may not necessarily be a quality prediction of the selectivity in the bulk cage solid. Our analysis of potential energies of adsorption sites in/on the cage molecules in Fig. .1, however, suggests that the dominant adsorption site in cages exhibiting the highest simulated Xe/Kr selectivity tend to be internal to their cavity; hence false positives may be unlikely unless the internal sites are blocked.