The c(4 x 2) reconstruction of the (001) plane was studied by using X-ray diffraction techniques at 150K in order to measure the in-plane reflections and out-of-plane intensities of fractional order rods. The structure consisted of an alternating arrangement of buckled dimers (with a tilt angle of 19) along the [110] and [110] surface directions. The dimer rows did not lie straight along the [110] direction, but zig-zagged slightly; with an amplitude of 0.0340nm.

S.Ferrer, X.Torrelles, V.H.Etgens, H.A.Van der Vegt, P.Fajardo: Physical Review Letters, 1995, 75[9], 1771-3