1. School of Materials Science and Engineering Rare Earth and Inorganic Functional Materials Center Nankai University Tianjin 300350 P. R. China
2. China State Key Laboratory of Rare Earth Resource Utilization Changchun Institute of Applied Chemistry Chinese Academy of Sciences Changchun Jilin 130022 P. R. China
3. University of Chinese Academy of Sciences Beijing 100049 P. R. China
4. Theoretical Division Los Alamos National Laboratory Los Alamos NM 87545 USA
5. Department of Chemistry Institute for Functional Nanomaterials University of Puerto Rico San Juan USA
6. Department of Chemistry and Biochemistry Utah State University 0300 Old Main Hill Logan UT 84322-0300 USA