Au(111): A theoretical study of the surface reconstruction and the surface electronic structure

On the reconstructed Au(111) surface, atoms on the surface layer occupy both the hcp and the fcc sites. Using first-principles calculations to obtain the surface energies of the system with the top Au layer occupying the fcc, hcp, top, and bridge sites, we found that the hcp site is only 1 mRy per surface atom higher in energy than the fcc site. The complex Au(111) reconstruction is then discussed with use of a two-dimensional Frenkel-Kontorowa model. We calculated the surface band structure of the Au(111) surface along high-symmetry lines in the surface Brillouin zone, with the top layer occupying the fcc, hcp, and bridge sites. We found that the surface electronic structure is almost independent of the position of the top layer.