1. Department of Chemistry, Gakushuin University, Mejiro, Toshima-ku, Tokyo 171-8588, Japan
2. Bayerisches Geoinstitut, University of Bayreuth, 95440 Bayreuth, Germany
3. Center for High Pressure Science and Technology Advanced Research, Beijing, 100094, China
4. ‡ Present address: Faculty of Education, University of Miyazaki, 1-1 Gakuen Kibanadai Nishi, Miyazaki, 889-2192 Miyazaki, Japan