1. Department of Inorganic Chemistry, Faculty of Science, Charles University, Hlavova 2030/8, 128 43 Prague 2, Czech Republic
2. Department of Chemical and Geological Sciences, University of Cagliari, S.S. 554 bivio per Sestu, 09042 8 Monserrato, CA, Italy
3. Institute of Macromolecular Chemistry, Academy of Sciences of the Czech Republic, 162 06 Prague 6, Czech Republic
4. Department of Physical and Macromolecular Chemistry, Faculty of Science, Charles University, Hlavova 2030/8, 128 43 Prague 2, Czech Republic
5. Department of Condensed Matter Physics, Faculty of Mathematics and Physics, Charles University, Ke Karlovu 5, 121 16 Prague 2, Czech Republic
6. Institut Laue-Langevin, 71 Avenue des Martyrs, F-38042 Grenoble, France