Studies of the Raman spectra of cyclic and acyclic molecules: Combination and prediction spectrum methods

► Derived Raman spectra of cyclic and acyclic organic chemicals. ► Theoretically calculated vibrational wavenumbers with the B3LYP method using the 6-31+G(2df,p) basis set. ► Applied the combination and prediction spectrum method (CPSM) to hydroxymethyl furfural and levulinic acid. ► Demonstrated that CPSM is a feasible method for predicting vibrational spectra of complex molecules.