Optical and infrared properties of dichromate ion in alkali halides

Two electronic bands arising from the t1 → 2e and t1 → 3t2 transitions are observed in the region ≈ 360 nm and ≈ 250 nm in alkali halide crystals doped with Cr2O2-7. These bands split and also show well resolved fine structure at 77°K. The fine structure is explained on the basis of vibrational frequencies superimposed on electronic spectra. Infra-red spectra of these crystals show three prominent bands. © 1972.