1. Institute for High Pressure Physics Russian Acad, of Sciences. Troitsk, Moscow Region, 142092, Russia
2. International Laboratory of High Magnetic Fields and Low Temperatures, Gajowicka 95, Wroclaw 53-529, Poland
3. Institute of General and Inorganic Chemistry, Russian Acad, of Sciences, Leninskii pr. 31, Moscow, 117907, Russia
4. Russian Research Center ‘‘Kurchatov Institute’’, Kurchatov sq. 1, Moscow, 123182, Russia