Resonant photoemission and Auger emission from molecules

A review of recent research on free molecules using narrow-band undulator radiation from a third-generation synchrotron radiation source in combination with high-resolution electron spectroscopy is given. The reviewed work has been performed at beam line 1411 at the MAX II electron storage ring at MAX-Laboratory in Lund, Sweden. This new facility makes it possible to study deexcitation spectra associated with resonant excitation around the C 1s, N 1s, O 1s and F 1s edges, under full vibrational resolution well within the requirements for resonant Raman conditions. Examples from several molecules show that this spectroscopy is invaluable for studying small molecules on the quantum chemical level. The simplest form of lifetime vibrational interference theory is not adequate for describing the experiments at this level. The experimental results will therefore be compared to more advanced theoretical models, including several new types of resonance mechanisms. (C) 2001 Elsevier Science B.V. All rights reserved.