Investigation of optical spectra and local structure for (CrF6)3− cluster in Cs2NaAlF6:Cr3+ and Cs2NaGaF6:Cr3+ systems

The unified calculations of EPR, optical spectra for Cr3+ in Cs2NaAlF6 and Cs2NaGaF6 are made based on the complete energy matrices. The results demonstrate that Cr3+ substitute at two inequivalent M3+ sites rather than Na+ or Cs+. The relationship between the structure and the temperature has been discussed.