First-principles study of electronic structures of CdMoO4 crystal containing F-type color centers

The electronic structures of the CdMoO4 crystal containing F-type color centers are studied within the framework of the fully relativistic self-consistent Dirac-Slater theory, using a numerically discrete variation (DV-Xα) method. It is concluded from the calculated results that the F and F+ color centers have donor energy levels in the band gap and the optical transition energies are 1.761 eV and 1.941 eV, which correspond to the 706 nm and 640 nm red absorption bands, respectively. So the CdMoO4 crystal should exhibit a blue-green color. It is predicted that the 650-750 nm absorption bands and the bluish green color originate from the F and F+ color centers in the CdMoO4 crystal. (copyright 2008 WILEY-VCH Verlag GmbH and Co. KGaA, Weinheim) (orig.)