CO on Cu(001): An inverse-photoemission study

Abstract
Inverse photoemission is used to examine the adsorbate-induced unoccupied band structure of the c(2×2)CO/Cu(001) adsorption system. As in an earlier study we observe two adsorbate-induced peaks above the Fermi level. By comparing with a simple tight-binding model we associate one unoccupied adsorbate band with the molecular 2π level and another band with a substrate surface band interacting with the molecular 5σ level.