1. Université de Rennes 1, Unité Sciences Chimiques de Rennes, UMR 6226 CNRS-UR1, Campus de Beaulieu CS74205, F-35042 Rennes, Cedex, France
2. Nikolaev Institute of Inorganic Chemistry, Siberian Branch of the Russian Academy of Science, 3 Acad. Lavrentiev Prosp., 630090 Novosibirsk, Russia
3. National Institute for Materials Science, 1-1 Namiki, Tsukuba, Ibaraki 305-044, Japan