LEED intensity‐versus‐energy curves have been measured with clean, cleaved, and subsequently annealed Si (111) surfaces between 30 and 250 eV. After cleavage the surfaces exhibited single‐domain 2×1 LEEDpatterns. The analysis of the observed peak energies in the double‐diffraction picture confirms Haneman’s model of the 2×1 structure and gives: (1) The first layer is uniformly displaced inward by 0.08 Å and is buckled by 0.47 Å, (2) the spacing between second and third layer is relaxed by 0.22 Å. After anneals at approximately 300°C an apparent ′′1×1′′ structure is observed. The analysis of the measured I–V spectra reveals for this structure: The spacing between the first two layers is enlarged by 0.04 Å, while the distance between second and third layer is nearly unchanged. The I–V spectra of the final 7×7 structure, which are observed after anneals above the conversion temperature, are very similar to those of the ′′1×1′′ structure.