Minerals from Macedonia. XXVII: Theoretical and experimental study of the vibrational spectra of endemic nežilovite

Endemic mineral nežilovite was studied by vibrational spectroscopy (IR and Raman), quantum theoretical methods and X-ray powder diffraction. Experimental Raman as well as the higher-frequency region of the infrared spectra of this mineral closely resembles to the corresponding spectra of magnetoplumbite-group minerals, while the appearance of the lower-frequency part of the IR spectra is markedly similar to the corresponding region in Ba-ferrite. Essentially, all bands in the experimental spectra were tentatively assigned. In most cases, the assignments were either supported or implied by the theoretical data obtained on the basis of plane-wave pseudopotential density functional theory (DFT) calculations.