Lattice vibration and dielectric properties of CaNb2O6

The lattice vibration and dielectric properties of CaNb2O6 have been studied using density functional perturbation theory. The complete set of the zone center optical phonon modes and frequency dependent dielectric function of the CaNb2O6 have been determined. The assignment of mode vibrations to all of the optical phonon frequencies was made by analyzing the eigen displacements. We find that the highest frequency mode of all the Raman active symmetry species is due to NbO6 stretching vibration. Our calculated dielectric functions and quality factor are in very good agreement with the corresponding experimental results. •Lattice vibration and dielectric properties of columbite-type CaNb2O6 crystal are studied, using density functional perturbation theory.•The correspondence between optical mode frequencies and vibrations have been specified.•The highest frequency mode of all the Raman active symmetry species is due to NbO6 stretching vibration.