The right-hand-side panel of Figure shows the vibrational modes of water on the metal surfaces and in bulk. The narrow band of the water bending mode is shifted to a lower frequency from the bulk value of ca. 1700 cm -1 on Pd, Pt, and Rh, where the water density distribution ρ(z) shows two peaks at the interface region. Since the bending mode doesn't couple strongly to the movement of other water molecules, the frequency decrease reflects softer intramolecular bonds, which is likely caused by partial charge transfer from adsorbed water molecules to the surface. The O-H stretching mode around 3500 cm -1 in the bulk liquid phase is rather broad due to the dynamic forming and breaking of the hydrogen bonds. The small red-shift of the stretching mode on Pd, Pt, and Rh indicates softer O-H bonding at these surfaces. On Ag, both vibrational modes are relatively close to their bulk liquid counterparts. On Au, however, the surface seems to induce a blueshift in the stretching mode while the bending mode remains at the bulk position. The blue-shift is peculiar since the Auwater has the weakest chemisorption and it would be expected that the DoS were then more bulk-like, similar to the Ag case. The apparent blue-shift may result if a hydrogen-bonding related broadening mechanism is effectively suppressed. We suggest that the blue-shift of the stretching mode indicates a weaker or looser hydrogen bond network at the Au-water interface.