Department of Inorganic Chemistry, Indian Association for the Cultivation of Science, Kolkata 700 032, India, Department of Inorganic Chemistry, Universita Karlova, Albertov 2030, 128 40, Prague 2, Czech Republic, College of Chemistry and Molecular Engineering, State Key Laboratory of Rare Earth Materials Chemistry and Applications, Peking University, Beijing 100871, P. R. China, Department of Physics, The Graduate School of the Chinese Academy of Sciences, P.O. Box 3908, Beijing 100039, P. R. China(At 2004-01-14)
