Low-energy electron diffraction studies show that the clean Pb(110) surface had a c(2 x 4) superstructure below about 425K. It was attributed to surface stress relief by increased packing density but a dimensionally enhanced Kohn anomaly-induced lattice distortion cannot be excluded.

A New Surface Reconstruction - Pb(110). A.Pavlovska, E.Bauer: Europhysics Letters, 1989, 9[8], 797-802