Effect of the partial charge distributions in the ZIF-8 framework on the adsorption of CO2 as assessed by Gibbs Ensemble Monte Carlo simulations

The effect of the partial charge distributions on the adsorption of CO2 molecules in ZIF-8 framework has been obtained using GEMC simulations. The charge models are derived from the ab initio electrostatic potential surfaces of framework fragments. The signs of the atomic charges obtained with the MK model are more consistent with respect to the basis set than those obtained from the other models. The charges on the H1 and H2 atoms are found to have a notable effect on the amount of absorbed CO2, in agreement with a previous mention that these hydrogen sites are the favored absorption sites.