  Using x-ray diffraction Ghose et al. [Surf. Sci. {\bf 581} (2005) 199] have
recently produced a structural model for the quantum-wire surface Si(553)-Au.
This model presents two parallel gold wires located at the step edge. Thus, the
structure and the gold coverage are quite different from previous proposals. We
present here an ab initio study using density functional theory of the
stability, electronic band structure and scanning tunneling microscopy images
of this model.
