High-Order Resonance Interactions in HDO: Analysis of the Absorption Spectrum in the 14 980-15 350 cm(-1) Spectral Region.
The absorption spectrum of the HDO molecule recorded by intracavity laser absorption spectroscopy in the 14 980-15 350 cm(-1) spectral region was assigned and modeled in the frame of the effective Hamiltonian approach. The spectrum (496 lines) results, mainly, from transitions to the rotational sublevels of the (014) bright state. An important number of transitions involving the (142) and (0 12 0) highly excited bending states could be identified, borrowing their intensities through high-order resonance interactions with the (014) state. An original feature shown by the present analysis is that all the transitions involving unperturbed energy levels of the (014) state are exclusively of A type, while both A- and B-type transitions are observed when the upper states are perturbed by the resonance interactions. One hundred forty-five energy levels of the three interacting states were derived from the spectrum and fitted to the effective rotational Hamiltonian in Pade-Borel approximants form with 29 varied parameters yielding an rms deviation of 0.038 cm(-1). A few energy levels are affected by additional local resonances with perturbers which have been identified. Finally, 48 transitions of the very weak 6nu(1) band were assigned and fitted as an isolated band. Copyright 2000 Academic Press.
Naumenko
O
Laboratoire de Spectrométrie Physique (associated with CNRS, UMR 5588), Université Joseph Fourier de Grenoble, B.P. 87, Saint-Martin-d'Hères Cedex, 38402, France
Campargue
A