Is the Observed Photoemission Peak near the Fermi Level on the (100) Face of Mo a Surface State

By use of synchroton radiation in the range 12 to 40 eV, angle-resolved photoemission spectra of the (100) Mo surface have been observed which exhibit a sharp peak near the Fermi level. This structure points strongly in the normal direction, it is very sensitive to surface contamination, and its position does not change with photon energy. A similar peak has been attributed in the past to a surface state. We show that it is most likely due to a combination of a surface resonance and a d-band edge on both experimental and theoretical grounds.