The infrared spectrum is calculated by summing the calculated spectra of the three rotamers. The harmonic and anharmonic calculated infrared spectra for non-, mono- and di-deuterated isotopomers are shown in Fig. 4–6, respectively. Tables 5–7 show the calculated infrared spectral intensities (before Lorentzian normalization) for the normal modes of the non-, mono- and di-deuterated isotopomers.