1. RIKEN CLST-JEOL Collaboration Center, Tsurumi,
Yokohama, Kanagawa 230-0045, Japan
2. JEOL RESONANCE Inc., 3-1-2 Musashino, Akishima, Tokyo 196-8558, Japan
3. Department of Synthetic Chemistry and Biological Chemistry, Graduate School of Engineering, Kyoto University, Katsura, Nishikyo-ku, Kyoto 615-8510, Japan