Atomic Structure and Energetic Stability of the Bi–covered InAs(110) Surface

We have performed ab initio calculations of the atomic structure and energetic stability of the Bi–covered InAs(110) surface. The calculations were performed within the density–functional theory, using norm– conserving fully separable ab initio pseudopotentials. Two experimentally proposed structural models have been considered: (1×1)–ECLS and (1×2). Our total energy calculations indicate that the formation of the (1×2) model is energetically more favourable than the (1×1) model by 41 meV/(1×2). The calculated equilibrium geometries, for the InAs(110)–Bi(1×1) and –Bi(1×2) surfaces, show in general a good agreement with the experimental x-ray measurements carried out by Betti et al. [Phys. Rev. B, 59, 15760 (1999)].