Raman spectra and thermal disordering of the crystalline structure of benzene

Disordering of rotational degrees of freedom of molecules in a benzene crystal is investigated from Raman spectra. Nonuniform smearing of the spectrum of librational vibrations to the wing of the Rayleigh line is established. The changes observed are interpreted on the basis of calculations of frequencies, intensities, vibration modes, and barriers to molecular reorientations in the crystal by the method of atom-atom potentials. The line broadening in the spectrum of external vibrations by reorientations of molecules in the crystal as a function of their mode is analyzed. Translated from Zhurnal Prikladnoi Spektroskopii, Vol. 66, No. 3, pp. 394–400, May–June, 1999.