1. Chair of Inorganic Chemistry II, Ruhr University Bochum, Universitätsstrasse 150, 44801 Bochum, Germany, http://www.ruhr‐uni‐bochum.de/aci2/
2. Division of Chemistry, Graduate School of Science, Kyoto University, Kitashirakawa‐Oiwakecho, Sakyo‐ku, Kyoto 606‐8502, Japan, http://kuchem.kyoto‐u.ac.jp/ossc/index_eng.html
3. Core Research for Evolutional Science and Technology (CREST), Japan Science and Technology Agency (JST), 7, Gobancho, Chiyoda‐ku, Tokyo 102‐0076 Japan
4. Research Laboratory for High Voltage Electron Microscopy, Kyushu University, 744 Motooka, Nishi‐ku, Fukuoka 819‐0395, Japan