Structure of adsorbate inverse photoemission spectra: A model hamiltonian study

We present an Anderson-Newns Hamiltonian model of inverse photoemission spectra (IPES) of adsorbates on metals. We find that besides image screening, another screening mechanism may operate in IPES when intra-adsorbate electron correlation is strong and the adsorbate has filled levels near the Fermi energy of the metal. While image screening results in spectral shifts and the appearance of plasmon satellites, this new screening mechanism gives a doublet structure to the IPES. We also find that the hybridization of the adsorbate affinity levels with the unoccupied metal levels plays a crucial role in determining both the width and energy of the spectra. © 1986.