1. Inorganic Materials Science, Faculty of Science & Technology, and Mesa+ Institute for Nanotechnology, University of Twente, P.O. Box 217, 7500 AE, Enschede, The Netherlands
2. Inorganic Chemistry, Royal University of Technology, 100 44, Stockholm, Sweden
3. Université Louis Pasteur, Laboratoire de Chimie Moléculaire et de RMN du Solide, Institut Le Bel, 4 Rue Blaise Pascal, 67070 Strasbourg, France
4. Department of Chemistry, SLU, Box 7015, 75007 Uppsala, Sweden