Analysis of an Overtone Band of CH3D at 11 931 cm−1

Abstract The vibrational overtone band of monodeuterated methane (CH 3 D) at 11 931 cm −1 was recorded by intracavity photoacoustic spectroscopy at 100 K with a resolution limited by Doppler broadening. Although the J and K rotational structures of the parallel band are clearly resolved, rotational perturbations result in an irregular subband structure.