The Raman Spectrum of NaNO 2 in the Ferroelectric Phase

The Raman spectrum of a NaNO 2 single crystal in the ferroelectric phase is obtained and the polarization of the lines is investigated. The forms of normal vibrations are considered on the basis of symmetry coordinates and the intensity of lines. Formulae for translational vibrations are derived and numerical calculations are performed taking into account shortrange repulsive forces between nearest neighbours and long‐range Coulomb forces.