We model the potential energy E = E(n, R (n) ) of the system in microstate (n, R (n) ) by treating the adsorbate-COF and adsorbate-adsorbate interactions as pairwise additive and described by 12-6 Lennard-Jones interatomic potentials (parameters from the Universal Force Field, Lorentz-Berthelot combining rules, 111 truncated to neglect interactions beyond 14 Å). We apply periodic boundary conditions to mimic the crystalline COF.