Based upon first-principles total-energy calculations, the chemical identity and adsorption site of the adatoms observed in scanning tunnelling microscopy of the SiC(00•1)(√3 x √3) surface were determined. The calculations indicated that Si adatoms were preferred over C adatoms for the entire allowed range of Si and C chemical potentials. In addition, It was found that the adatoms preferred the T4 site over the H3 site for both Si and C. Based upon these results, a model was proposed for the C-rich 6√3 x 6√3 reconstruction.

Theory of the Adatom-Induced Reconstruction of the SiC(0001)√3x√3 Surface. J.E.Northrup, J.Neugebauer: Physical Review B, 1995, 52, R17001-4