The InSb(001) surface has been studied experimentally, using room temperature scanning tunnelling microscopy (RT STM), and theoretically, using ab initio density functional theory (DFT) calculations. RT experimental STM images show bright lines running along the bulk crystal [110] direction. Resolved features between the bright lines whose appearance depends on the applied bias voltage confirm clearly the c(8×2) reconstruction of this surface. Our calculations, which are reported for this surface for the first time, include the reconstructed 4×2 and c(8×2) surfaces, the latter according to the so-called ζ-model proposed previously by Lee et al and Kumpf et al. A 'defective' structure proposed previously by Kumpf et al, which contains an extra In atom within a top bilayer is also considered. In all cases, we obtained stable structures. Calculated STM images for the c(8×2) reconstruction obtained using the Tersoff-Hamann approximation compare extremely well with the experimental ones. We also find that the defect structure may not be clearly visible in the STM images. Finally, a brief discussion is given on the other, although closely related, phase of the same surface observed previously in low temperature (LT) experimental STM images (Goryl et al 2007 Surf. Sci. 601 3605).
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