1. Institute of Crystallography; Russian Academy of Sciences; 119333 Moscow Russia
2. Institute of Crystallography; University of Cologne; 50939 Cologne Germany
3. Institute of Optics and Atomic Physics; Technical University of Berlin; 10623 Berlin Germany
4. Institute for Laser Science; University of Electro-Communications; Tokyo 182-8585 Japan
5. Department of Inorganic Chemistry; Faculty of Science; Charles University in Prague; 12840 Prague Czech Republic