Terahertz and Raman spectra of non-centrosymmetrical organic molecular crystals

•The terahertz spectra was obtained for selected organic crystals.•The Raman spectra was obtained for selected organic crystals.•The dielectric constant behavior was examined for the crystals.•The LO-TO splitting was found for three crystals.

The terahertz waves have been applied to the spectroscopy of molecular crystals. The group based on hybrid organic–inorganic crystals like triglycine zinc chloride, triglycine sulphate, triglycine selenate, diglycine hydrobromide, diglycine hydrochloride, diglycine lithium nitrate, glycine lithium nitrate has been considered. The dispersion relation phonon–polariton have been shown between 10 cm−1 and 80 cm−1 for diglycine lithium nitrate, triglycine zinc chloride, and diglycine hydrobromide.