1. Fachbereich C-Mathematik und Naturwissenschaften, Bergische Universitaet Wuppertal, D-42119 Wuppertal, Germany
2. Quantum Chemistry Division, Graduate School of Integrated Science, Yokohama City University, 22-2 Seto, Kanazawa, Yokohama 236-0027, Japan
3. Division of Natural Sciences, International Christian University, Osawa 3-10-2, Mitaka, Tokyo 181-8585, Japan
4. Graduate School of Science, Kyushu University, Fukuoka 815-8611, Japan