1. Joint Institute for High Temperatures, Russian Academy of Sciences, 125412 Moscow, Russia
2. L.D. Landau Institute for Theoretical Physics, Russian Academy of Sciences, 117940 Moscow, Russia
3. Ural Federal University, 620002 Ekaterinburg, Russia
4. Institute of Metallurgy, Ural Branch of Russian Academy of Sciences, 620016 Ekaterinburg, Russia
5. Moscow Institute of Physics and Technology, 141700 Moscow, Russia
6. Institute for High Pressure Physics, Russian Academy of Sciences, Troitsk 108840, Moscow, Russia