Self-consistent calculations of oxygen monolayers on Al(111) films

We calculate the energy bands, work function, Al $2p$ chemical shift, and oxygen binding energy for a six-layer Al(111) film with oxygen overlayers at three distances from the Al surface plane. We find that the experimental work function, chemical shift, and oxygen $2p$ surface resonance bands cannot be explained with a simple oxygen overlayer at any distance and speculate that the correct configuration may involve an underlayer.