1. Institute of Crystallography, Russian Academy of Sciences, 59 Leninsky Pr., 117333 Moscow, Russia
2. A.N.Nesmeyanov Institute of Organoelement Compounds, Russian Academy of Sciences, 28 Vavilov St., Moscow, 119991 Russia
3. Indiana University, Department of Chemistry, 800 East Kirkwood Avenue, Bloomington, Indiana 47405, United States
4. EMBL, Hamburg Outstation, Notkestrasse 85, D-22603 Hamburg, Germany