After assessing the current status concerning the interpretation of Si 2p core-level shifts in Si-O systems, we model the atomic structure of the Si(001)-SiO2 interface using recent photoemission data obtained with synchrotron radiation. Our model structure reproduces the amount, the distribution, and the location of silicon atoms in intermediate states of oxidation. Our model also shows a SiO2 density in the neighborhood of the interface consistent with X-ray reflectivity measurements. (C) 2002 Elsevier Science B.V. All rights reserved.