1. Center for High Pressure Science & Technology Advanced Research Shanghai 206203 P. R. China
2. Department of Chemistry and BiochemistryNorthern Illinois University DeKalb IL 60115 USA
3. Chemical Sciences and Engineering DivisionArgonne National Laboratory Lemont IL 60439 USA
4. State Key Laboratory of Rare Earth Materials Chemistry and ApplicationsCollege of Chemistry and Molecular EngineeringPeking University Beijing 100871 P. R. China
5. CAS Key Laboratory of Materials for Energy ConversionShanghai Institute of CeramicsChinese Academy of Sciences Shanghai 200050 P. R. China