Exploiting the very recent potentialities
of state-of-the-art quantum
chemical simulations of crystalline solids, unpolarized Raman spectra
of α and γ polymorphs of Nylon-6 obtained through periodic
density functional theory calculations are presented for the first
time. The computed spectra are compared with the experimental spectra
reported in the literature and allow a detailed interpretation to
be proposed of the patterns observed, identifying unambiguous Raman
marker bands of the different phases. The calculations of single crystal
directional intensities gave the further possibility to predict the
polarization properties of the Raman spectra of these polymorphs:
considering in particular the α phase, polarized Raman spectra
have been computed and showed a very good agreement with measurements
previously reported for uniaxially oriented samples
