For surrogate modeling, we must define a space in which we mathematically represent each COF as a point in a continuous space. Inspired by several computational studies revealing the structure-property relationships of porous materials for Xe/Kr separations, we elected to represent each COF with a vector x ∈ R 14 that lies in a continuous space, listing its following structural (computed from Zeo++ 91 ) and compositional features derived from its crystal structure: density, gravimetric surface area, void fraction, largest included sphere diameter, and elemental fractions of metals, halogens, phosophorus, sulfur, nitrogen, silicon, hydrogen, carbon, oxygen, and boron. See Fig. . We min-max normalized the features.