The roughening transition of the (110) faces of these metals was described in terms of the creation of anisotropic defects which were similar to the missing rows which appeared in the reconstruction of Ir, Pt, and Au. This result was combined with an anisotropic version of the exactly soluble 6-vertex model, and was used to calculate the scattering intensities of He atoms and X-rays.

A.Trayanov, A.C.Levi, E.Tosatti: Europhysics Letters, 1989, 8[7], 657-62