1. The Institute of Problems of Chemical Physics, Russian Academy of Sciences, Prospect Akademika Semenova 1, 142432 Chernogolovka, Russia
2. Department of Chemistry, Lomonosov Moscow State University, Leninskie gory 1/3, 119991 Moscow, Russia
3. Atomic and Molecular Physics Division, Harvard-Smithsonian Center for Astrophysics, 60 Garden St, Cambridge, Massachusetts 02138, USA