The Absorption Spectrum of HDO in the 16 300–16 670 and 18 000–18 350 cm−1 Spectral Regions

Abstract

The absorption spectrum of HDO has been recorded by Intracavity Laser Absorption Spectroscopy in the 16 300–16 670 and 18 000–18 350 cm−1 spectral regions corresponding to the weak 2ν2 + 4ν3 and ν2 + 5ν3 bands, respectively. The ν2 + 5ν3 band centered at 18 208.434 cm−1 was found almost isolated and has been satisfactorily reproduced in the frame of the effective Hamiltonian model. On the other hand, the 2ν2 + 4ν3 band at 16 456.201 cm−1 is strongly perturbed as the (0 2 4) bright state is involved in a complex interaction scheme including the (1 0 4), (5 0 1), (1 5 2), and (1 11 0) states. The rovibrational assignment of these interacting states was greatly helped by the high-accuracy ab initio predictions performed by D. Schwenke and H. Partridge [J. Chem. Phys. 000–000 (2000)]. They could be partly modeled by an effective Hamiltonian which has allowed the assignment and reproduction of most of the observed transitions.