Manifestation of Vacancies in a Spectrum of Organic Molecular Crystal   Lattice Vibrations
  Using a method Raman of spectroscopy and considering a non-uniformity of allocation of vacancies in a monocrystal, it is shown that lines with the small intensity (caused by presence of vacancies) have a major intensity in the sample of a larger size than in the sample of a smaller size. Increase of an intensity of lines at vacancy concentration increase can reveal which lines are related to presence of vacancies in the sample. For a p-dichlorobenzene, it is lines of a small intensity in a spectrum of the lattice oscillations in the field of 70 cm^{-1}. 
M.A. Korshunov