As mentioned earlier, one of the target applications of the Q I polymer membrane is nanofiltration. Thus permeability of water and other molecules through the membrane is of immense interest. Experimentally, transport properties such as permeability of solutes are measured by monitoring the pressure-driven flux and the change in solute concentration across the membrane. It is difficult to create asymmetric concentrations and calculate transport across a membrane in all-atom MD simulation with these large unit cells. To provide a qualitative comparison, we therefore calculated the mean square displacement (MSD) and diffusion coefficient and used these quantities to approximate the relative size of transport properties such as permeability and selectivity. We calculated the mean square displacement (MSD) using the time series r t of the position of the