High resolution vibration-rotation spectrum of the D2O molecule in the region near the 2ν1+ ν2+ ν3absorption band

Abstract
The high resolution Fourier transform spectrum of the D20 (ν = ν1 + ν2/2 + ν3 = 3.5) polyad was analysed within the framework of the Hamiltonian model taking into account resonance interactions between the seven states (310), (211), (112), (013), (230), (131) and (032). Transitions belonging to the 2ν1 + ν2 + ν3, 3ν12 and 3ν2 + 2ν3 bands were assigned in the experimentally recorded spectrum. This provided the possibility of obtaining spectroscopic parameters of the ‘visible’ states (211), (310) and (032) and of estimating the band centres, and the rotational and resonance interaction parameters of the ‘dark’ states (112) and (131).