Electronic structure of Cr4+: Y3Al3O2

The energy level diagram of the tetrahedral-coordinated,nated Cr4+ ion in Y 3Al5O12 is calculated using the model of exchange charges of the crystal fi eld theory taking into account the interaction between the F-3 and P-3 term s. Comparison of the obtained energy level diagram with experimental absorp tion spectra of this crystal shows good agreement between theoretical calcu lations and the experimental data. Pairs of the energy levels involved in t he transitions corresponding to the absorption bands of Cr4+ : Y3Al5O12 are determined.