A low-energy electron diffraction intensity analysis of the Si(001)2 x 1 structure led to exclusion of two of the most widely discussed models for surface reconstruction. These were models involving surface dimers or surface vacancies. A different model was presented that provides acceptable agreement between calculated and observed intensity spectra. The model was based on the idea of conjugated surface chains advanced by Seiwatz (1964), and involves distortions of both the first and the second atomic layers. The model was consistent with the rare observation of four-fold periodicities on Si(001) and suggests that small surface concentrations of carbon could be important.

Probable Atomic Structure of Reconstructed Si(001)2 x 1 Surfaces Determined by Low-Energy Electron Diffraction. F.Jona, H.D.Shih, A.Ignatiev, D.W.Jepsen, P.M.Marcus: Journal of Physics C, 1977, 10[4], L67-72