1. State Key Laboratory of Rare Earth Resource Utilization
2. Changchun Institute of Applied Chemistry, Chinese Academy of Sciences
3. Changchun 130022
4. P. R. China
5. University of Science and Technology of China
6. European Theoretical Spectroscopy Facility
7. Institute of Condensed Matter and Nanosciences
8. Université catholique de Louvain
9. B-1348 Louvain-la-Neuve
10. Belgium