1. Optics R&D Center, CANON Inc., Utsunomiya 323-3298, Japan
2. CCSE, Japan Atomic Energy Agency, Kashiwa, Chiba 277-8587, Japan
3. CREST (JST), Kawaguchi, Saitama 332-0012, Japan
4. Computational Condensed Matter Physics Laboratory, RIKEN, Wako, Saitama 351-0198, Japan
5. Computational Materials Science Research Team, RIKEN AICS, Kobe 650-0047, Japan
6. Waseda University Honjo Senior High School, Honjo, Saitama 367-0032, Japan
7. Department of Information Systems Science, Graduate School of Engineering, Utsunomiya University, Utsunomiya 321-8585, Japan