Run-time: ca. 230 min. The high-fidelity simulation constitutes a Markov chain Monte Carlo (MC) simulation of the COF in the binary grand-canonical (BGC) ensemble. During the molecular simulation, generally the COF hosts both and multiple Xe and Kr adsorbates; these adsorbates enter/leave the COF from/to the gas phase and move around in the pores of the COF to explore configurations. The key measurable during the BGCMC simulation is the average number of adsorbates in the COF system, n , with n := [n Xe , n Kr ]. Our high-fidelity prediction of the adsorptive Xe/Kr selectivity of the COF is then