1. Guangzhou Institute of Geochemistry, Chinese Academy of Sciences, Guangzhou, Guangdong, China 510640
2. Department of Civil Engineering and Geological Sciences and Department of Chemistry and Biochemistry, University ofNotre Dame, Notre Dame, Indiana 46556, USA, Fax: +1‐574‐631‐9236
3. Chemistry Division, Argonne National Laboratory, Argonne, Illinois 60439, USA
4. Department of Crystallography, University of Kiel, Kiel, 24118 Germany, Fax: +49‐431‐880‐4457
5. Department of Crystallography, St. Petersburg State University, 199034 St. Petersburg, Russian Federation