1. Department of Physics and Measurements, University of Chemistry and Technology, Technická 5, 16 628 Prague 6, Czech Republic
2. FZU - Institute of Physics - Czech Academy of Sciences, Na Slovance 1999/2, Prague 8, 182 21, Czech Republic
3. Department of Inorganic Chemistry, Charles University Prague, Faculty of Science, Hlavova 8, 12 840 Prague 2, Czech Republic