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