Despite starting from the same initial setup, one simulation exhibits twice the permeability of the other, while maintaining similar perm-selectivity. This suggests that membrane performance is not only influenced by the individual configurations of the polymer, but also by the specific simulation trajectories. The amorphous and flexible nature of the polymer allows gas molecules to explore different positions and pathways, leading to varying relaxation patterns and, consequently, different performance outcomes. This is evident in the comparison of density profiles for the two configurations, as shown in Fig. . Although both simulations begin with identical setup, in run 2, a clear CO 2 concentration gradient is developed across the membrane, while run 1 exhibits two concentration peaks near the outlet, indicating that some molecules become trapped in local minima within the pores. This results in a lower of a system is not an equilibrium thermodynamic state, and the final state the system settles in depends on the pathway.