Full density matrix functional calculations were performed to calculate structural properties and lattice dynamics of ZnO:Mn crystals. Wien2k and Phonon codes have been used. Both phonon dispersion curves and density of phonon states have been calculated. The phonon density of states has been calculated separately for Zn, Mn and O vibrations. The results of the calculations have been confronted with polarized Raman spectra. The symmetry of the Raman peaks assigned the Mn local vibrations has been identified and will be discussed. Fröhlich type resonant Raman scattering mechanism has been identified.