Additional insight into the water dynamics can be gained by using the linear correlation between the DoS at zero frequency and the water diffusion constant. The DoS at 0 cm -1 (Figure ) shows that the water diffusion within the 1WL on Au and Ag is similar to that in bulk water while on Pd, Pt, and Rh the water diffuses slightly slower. A similar trend holds for the entire water film, as shown in Figure ??. The translational DoS of water molecules within the 1WL can tentatively be understood by considering the four water diffusion mechanisms and barriers on different surfaces as suggested by Fang et al.: on Ag, water diffusion takes place through dimer translations with a barrier of 0.05 eV; on Pt, monomer translation has the lowest barrier of 0.18 eV; on Rh, a water exchange dominates the diffusion with a barrier of 0.1 eV; on Pd, all diffusion mechanisms have a barrier of 0.1 eV. In particular, monomer and dimer diffusion lead to total water displacements, but rotation and site exchange do not, which impacts both the diffusion constant and the correlated motion of the water molecules. Pt has the slowest water surface diffusion due to the higher barrier and single molecule translations. Water is most diffusive on Ag due to the low energy barrier and concerted motion of several water molecules. Pd presents an intermediate case with modest energy barriers and various diffusion pathways. Overall, the surface diffusion mechanisms and barriers qualitatively explain the interfacial part of the translational DoS on different metals.