IONIC STATES OF SMALL MOLECULES INVESTIGATED BY VIBRATIONALLY RESOLVED CORE-LEVEL PHOTOELECTRON SPECTROSCOPY U. Hergenhahn, A. Rüdel, E. E. Rennie, K. Maier, B. Kempgens, H. M. Köppe and A. M. Bradshaw Fritz-Haber-Institut der Max-Planck-Gesellschaft, Faradayweg 4-6, 14195 Berlin, Germany. Vibrationally resolved core-level photoelectron spectra have been measured for two closed-shell molecules, nitrogen and ethane, and two open-shell molecules, oxygen and nitric oxide, using highly monochromatic synchrotron radiaition. The analysis of these spectra have provided valuable and either previously unknown or unconfirmed information on the core-excited state of the molecule. For example, the exchange interaction present in NO has been resolved in the O1s-1 spectra for the first time.