1. Institut de Physique de Rennes, UMR UR1-CNRS 6251, Université de Rennes 1, 35042 Rennes, France
2. Argonne Photon Source (APS), ANL, 9700 South Cass Ave., Argonne, IL 60439, USA
3. European Synchrotron Radiation Facility (ESRF), 71, Avenue des Martyrs, Grenoble, France
4. Department of Chemistry, 213 CBC Building, Kansas State University, Manhattan, Kansas 66506-0401, USA
5. C.N.R.S., Directeur de Recherche, Department of Physics, University of Rennes 1, Campus de Beaulieu, Rennes, France