First-principles study on the F-type color centers in LiBaF3 crystals

摘要

The electronic structures of LiBaF3 crystals containing F-type color centers are studied in the framework of the fully relativistic self-consistent Direc-Slater theory, using a numerically discrete variational (DV-X alpha) method. The calculated results indicate that F and F-2 center have donor energy level in forbidden band. Their optical transition energies are 4.560 and 2.932 eV, respectively, which correspond to the 272 and 424 nm absorption bands. It predicts that the absorption bands observed at 270 and 430 nm could arise from the F and F-2 centers in LiBaF3 crystal, respectively, in LiBaF3 Crystals.