In the CHD2NO2 spectrum, the anharmonic treatment gives a modification in the shape of the (broad) band between 1230 and 1280 cm–1, mainly due to the 61 and 71 fundamental bands and from the 122 overtone band. A weak band appears around 1505 cm–1, due to the 101121 and 111121 combination bands from the four conformers. A low-intensity peak, corresponding to the 4151 combination band, appears around 2930 cm–1 from the anharmonic treatment. In addition to the peak at 3020 cm–1, corresponding to the 11 fundamental band of the H-eclipsed conformer, another low-intensity peak appears in the anharmonic spectrum around 2740 cm–1 and is due to the 52 overtone band.