1. Department of Chemistry, University of Munich (LMU), Butenandtstraße 5-13, 81377 Munich, Germany
2. ESRF-The European Synchrotron, 71 avenue des Martyrs, 38000 Grenoble, France
3. Institute for Mineralogy, Crystallography and Materials Science; Faculty of Chemistry and Mineralogy, Leipzig University, Scharnhorststraße 20, 04275 Leipzig, Germany
4. Lumileds Phosphor Center Aachen, Lumileds Germany GmbH, Philipsstraße 8, 52068 Aachen, Germany