Comment on "superstructures of lead monolayers electrochemically deposited on Ag(111)"

Using scanning tunneling microscopy, a long-wavelength pattern was observed by Muller et al. (Phys. Rev. B , 46, 12899 (1992)] in Pb monolayers on Pb(111) formed by underpotential electrochemical deposition. It is pointed out that the monolayer is incommensurate and so it should be described as having substrate-wavelength spacing and rotation angle, which are shown to depend on electrode potential.