The Q CO 2 and Henry coefficients of CO 2 and N 2 adsorption were determined by Widom's particle insertion algorithm 44 at 300K using the RASPA simulation package. 5,000 configurational-biased insertions of CO 2 and N 2 were used for each structure. Interaction energies between non-bonded atoms were computed using the Lennard-Jones (LJ) plus