  Using density-functional theory we investigate several properties of Al(111),
Al(100), Al(110), and stepped Al(111) surfaces. We report results of formation
energies of surfaces, steps, adatoms, and vacancies. For the adsorption and
diffusion of Al on flat regions of Al(111) surfaces we find the hcp site
energetically slightly preferred over the fcc site. The energy barrier for
self-diffusion on Al(111) is very low (0.04eV). Coming close to one of the two
sorts of close packed, monoatomic steps on Al(111), labeled according to their
{111} and {100} micro-facets, Al adatoms experience an attraction of <~ 0.1eV
already before direct contact with the edge of the step. This attraction has a
range of several atomic spacings and is of electronic origin. Upon arrival at
the lower step edge, the adatom attaches with no barrier at a low energy
five-fold coordinated site. Coming from the upper terrace, it incorporates into
the step by an atomic exchange process, which has a barrier below 0.1eV for
both sorts of close packed steps. The barrier for diffusion ...
