SUMMARY
In this work, theoretical study by using the DFT method on 3,5-bis(trifluoromethyl) phenyl isothiocyanate is reported. The FTIR and FT-Raman spectra of title compound were noted in the regions 4000–400cm–1; The HOMO, LUMO and Gap energy of these compounds have been calculated and reported in this paper. The theoretical study of such compound has not been reported. Thus, our aim to explain the spectroscopic properties on the basis of the DFT quantum chemical calculations and we are interested to explain the nonlinear optical analysis. The study of structural, vibrational spectroscopic studies and nonlinear optical properties for these compound could help to design more efficient functional photovoltaic organic compounds.