中文摘要：

对ca3sc2si3O12：ce3＋共掺杂N-3、sc3＋、Mn2＋、Mg2＋和Na＋进行第一性原理计算，研究不同的电荷补偿对发光中心Ce3＋的影响．首先利用密度泛函理论构建超晶胞模型对Ce3＋周围的局部结构进行了优化，然后通过CASSCF／CASPT2RASSI—SO计算得到Ce3＋的4f→5d跃迁能量．计算数据与实验光谱相吻合．实验光谱中的一个未知峰值理论分析确认是Sc3＋替代Si4＋导致的．

英文摘要：

Charge compensation plays a very important role in modifying the local atomic structure and moreover the spectroscopic property of an isolated luminescent center, and so has been widely adopted in phosphor designs. In this work, we carry out first-principles calculations on various cases of Ce3＋ centers in Ca3Sc2Si3O12 by considering the effects of the charge com- pensations related to N3-, Sc3＋, Mn2＋, Mg2＋, and Na＋. Firstly, the local structures around Ce3＋ are optimized by using density functional theory calculations with supercell model. The 4f→5d transition energies of Ce3＋ are then obtained from the CASSCF/CASPT2/RASSI-SO calculations performed on Ce3＋-centered embedded clusters. The calculated energies support the previous assignments of the experimental spectra. Especially, a previously unclear peak is identified to be caused by Sc3＋ substituting Si4＋. The results show that the first-principles calculations can be used as an effective tool for predicting and interpreting spectroscopic properties of the phosphors.