Resonant photoemission and Auger emission from molecules

A review of recent research on free molecules using narrow-band undulator r adiation from a third-generation synchrotron radiation source in combinatio n with high-resolution electron spectroscopy is given. The reviewed work ha s been performed at beam line 1411 at the MAX II electron storage ring at M AX-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 th e requirements for resonant Raman conditions. Examples from several molecul es show that this spectroscopy is invaluable for studying small molecules o n the quantum chemical level. The simplest form of lifetime vibrational int erference theory is not adequate for describing the experiments at this lev el. The experimental results will therefore be compared to more advanced th eoretical models, including several new types of resonance mechanisms. (C) 2001 Elsevier Science B.V. All rights reserved.