  We have performed a density functional study of fifteen different structural
models of the Si(557)-Au surface reconstruction. Here we present a brief
summary of the main structural trends obtained for the more favourable models,
focusing afterwards in a detailed description of the atomic structure,
electronic properties and, simulated STM images of the most stable model
predicted by our calculations. This structure is in very good agreement with
that recently proposed from X-ray diffraction measurements by Robinson et al.
[Phys. Rev. Lett. 88, (2002) 096194].
