Exhaustive search. An exhaustive search runs a high-fidelity simulation of Xe/Kr adsorption in each of the 609 COFs in X . While guaranteed to find the optimal COF x , an exhaustive search incurs a high cost because it fails to exploit (i) the cheap, low-fidelity simulations available and (ii) the information contained in the simulation data D [n] , about the relationship between the Xe/Kr selectivity of the COFs and their structural and compositional features in x, as the search proceeds.