 Because vibrational frequencies are specific to a molecule's chemical bonds and symmetry (the fingerprint region of organic molecules is in the wavenumber range 500–1500 cm−1), Raman provides a fingerprint to identify molecules.For instance, Raman and IR spectra were used to determine the vibrational frequencies of SiO, Si2O2, and Si3O3 on the basis of normal coordinate analyses.Raman is also used to study the addition of a substrate to an enzyme.