运用不可约张量算法和群理论构造了C3V对称晶场中3d5组态离子的252阶可完全对角化的微扰哈密顿矩阵。用此矩阵计算了Al2O3∶Fe3+晶体的光谱精细结构、零场分裂参量(D,a-F)、晶体结构, 其理论计算值与实验值相符合, 并研究了自旋四重态、自旋二重态分别对基态能级的影响, 证明了自旋四重态对基态能级的贡献是主要的, 自旋二重态对基态能级的贡献虽很小, 但却是不可忽略的。进一步研究了SO耦合作用、SS耦合作用对Al2O3：Fe3+晶体的光谱精细结构和零场分裂参量的影响, 结果发现SO耦合作用是最主要的, SS耦合作用也是不可忽略的。

The spectral fine structure, zero-field splitting parameters (D, a-F), crystal structure in Al2O3∶Fe3+ crystals were studied with the 252 ranks completely diagonalized Hamiltonian matrix of the 3d5 configuration in trigonal symmetry with irreducible algorithm and group theory. The results show that the contribution of spin quartet state on the ground-state energy levels is the most important, and the contribution of spin doublet state is small but cannot be neglected. The calculated results are in good agreement with the experimental results. The influences of spin-orbit interaction and spin-spin interaction on the spectra fine structure and zero-field splitting parameters were further studied, and the influence of spin-orbit interaction is dominant, but the influence of spin-spin interaction cannot be neglected.