1. Department of Chemistry, Kyoto University, Sakyo-ku, Kyoto 606
2. Department of Pure and Applied Sciences, University of Tokyo, Komaba, Meguro-ku, Tokyo 153
3. Institute for Solid State Physics, University of Tokyo, Roppongi, Minato-ku, Tokyo 106
4. Institute for Molecular Science, Okazaki 444
5. Department of Physics, Okayama University, Tsushimanaka, Okayama 700