The Fourier-transform Raman and infrared spectra were recorded in the solid state and interpreted by comparison with theoretical spectra derived from density functional theory (DFT) calculations. The [Mg((CH 3 ) 2 SO) 6 ] 2+ cation equilibrium geometry under S 6 symmetry, harmonic vibrational frequencies and related infrared and Raman scattering intensities were determined using B3LYP/6-311++G(3df,p) level of theory. Very good agreement between the theoretical and the experimental spectra justify an appropriateness of the used approach. Analogous, additional calculations were performed separately for the ClO4- anion within T d point group, at the same level of theory.