Dynamics of the molecular crystal lattice -- Calculation of frequencies and normal vibrational forms in the approximation of rigid molecules -- Solution of the dynamical problem with the consideration of the intermolecular vibration -- Devices and methods for the experimental investigation of organic crystals by means of the vibrational spectra -- Vibrational spectra and phase transitions in plastic crystals -- Reorientational motion of molecules in crystals without mesophases -- Stationary orientational disorder in trihalogen substituted methane crystals -- Vibrational spectra and phase transition in crystals with conformationally unstable molecules -- Application of vibrational spectra and AAP for the determination of structures and the investigation of phase transitions in crystals of phenanthrene and pyrene.