Figure 12.
Mean-square displacement (MSD) of DPPC molecules within the membrane x-y plane. The movement of the center of mass of the lipids was removed. The displacement at short-time is given in the inset. The MD system comprised 288 DPPC molecules. The short-time diffusion coefficient fitted from the slope of the MSD is 6 Å2/ns in the interval 0.03–0.05 ns and 4.5 Å2/ns in the interval 0.0–0.05 ns. The long-time diffusion coefficient fitted from the slope of the MSD is 0.25Å2/ns in the interval 10–20 ns and 0.1Å2/ns in the interval 30–50 ns.