Inner valence region of CO adsorbed on Pd(100)
The inner valence region of CO/Pd(100) p(2√2×√2)R45° has been studied by angular resolved photoemission at the Pd 4d Cooper minimum, and with resonant Auger spectroscopy at photon energies corresponding to the C 1s and O 1s x-ray absorption (XA) maxima of the unoccupied parts of the 2π*-Pd 4d hybrid (2πun). Previously unobserved inner valence states are revealed in the direct photoemission and are