To examine how water diffusion anisotropy depends on membrane properties in a multi-lamellar lipid bilayer system, we analyzed the water diffusion parallel to the membrane surface from all simulations in the NMRlipids Databank using the general workflows depicted in Figs. and. The parallel diffusion coefficient of water, D ∥ , decreases with reduced hydration and increases with the temperature, but dependencies on the membrane area per lipid, thickness, or fraction of charged lipids were not observed in Figs. and. Simulation results are close to the experimental values with low hydration levels in Fig. , but increase to approximately 50% higher than the experimental value for bulk water diffusion value (3.1× 10 -9 m 2 /s at 313 K ) with high hydration levels. This is not surprising as the most common water model used in membrane simulations, TIP3P, overestimates the bulk water diffusion . To estimate the diffusion anisotropy of water, D ⊥ /D ∥ , in multilamellar membrane system, the permeability coefficients of water through membranes were translated to perpendicular diffusion coefficients, D ⊥ , using the Tanner equation . The resulting perpendicular diffusion coefficients are approximately five orders of magnitude smaller than the lateral diffusion coefficients of water (Figs. ), which is at the upper limit of anisotropy estimated from experimental data . A significant increase in the diffusion anisotropy with membrane packing is observed, as D ⊥ /D ∥ deviates further from unity with decreasing area per lipid and increasing thickness in Figs. . This follows from decreasing water permeability with membrane packing (Figs. ), while lateral diffusion remains approximately constant (Figs. ).