MOFs with smaller pores, and therefore a higher density of framework atoms, are more sensitive to the LJ parameters. These materials are typically associated with lower adsorbate uptakes, and so we generally see higher scattering in the data at lower loadings, as shown in e.g., Figure ). This is further demonstrated in Figure , where the relative uptake of CO2 at 0.1 bar is plotted against the accessible void fraction of MOFs. In specific cases, confinement effects may also lead to very strong deviations in the adsorptive behaviours depending on the choice of the LJ parameters. For instance, OSOMIT, HELCUY, and GIMVAA -materials which contain Zn and have very narrow pore spaces -represent such exceptional cases. As an example, let us consider the adsorption isotherms of GIMVAA, as shown in the top left panel of Figure . The first feature to note about the behaviour of this material is the very strong uptake observed for the UFF+EQeq combination of parameters (green line). This is associated with the EQeq charges assigned to metal atoms in this structure, which are substantially higher than the charges assigned by the DDEC and Qeq schemes. Focusing on the other data in this panel (blue and red lines), we note that only UFF predicts an appreciable uptake of CO2, and much lower uptake for any other combination of parameters. This behaviour stems primarily from the difference in LJ Let us now consider the second scenario, when the LJ parameters for framework atoms are significantly different between UFF and Dreiding. If a MOF contains atom types for which the depth of the well in the interaction potential, 𝜀, between UFF and Dreiding is very different, we can anticipate some sensitivity of the adsorption behaviour to the choice of LJ FF. From Figure (c, g), we see that UFF generally predicts higher adsorbate uptakes.