However, aside from the obvious and well-known sources of uncertainty, such as the molecular forcefield, the results in Tab. 2 also pose a question on whether it is appropriate to use single component results to obtain perm-selectivity. In particular, the partial pressures of the components in the binary mixture of interest are 0.15 bar for CO 2 and 0.85 bar for N 2 . For CO 2 it is particularly lower than 1 bar CO 2 pressure in the single component setup.