THE 2$V_{3}$ AND 3$V_{3}$ BANDS OF $^{32}SO_{2}$: LINE POSITIONS AND INTENSITIES

Abstract

The weak overtone bands, 2$v_{3}$ and 3$v_{3}$, of $^{32}SO_{2}$ have been studied under high resolution and completely assigned. Both bands have been fit using a Watson Hamiltonian. The $3v_{3}$ band, important for the interpretation of the spectrum of the atmosphere of Venus, is essentially unperturbed although a few of the higher-order centrifugal distortion constant are anomalous. In order to fit the 2$v_{3}$ levels to within experimental accuracy ($\pm$$0.0008 cm^{-1}$), it is necessary to include a weak Fermi resonance with the nearby lying $v_{1}$+3$v_{2}$ state. The intensities of both bands have also been very satisfactorily fit although the 2$v_{3}$ band exhibits a striking Herman-Wallis effect. The integrated band intensities obtained for $2v_{3}$ and $3v_{3}$ are $S_{v}$ ($T=296) = 0.0995(20)$ and $0.0384(15) cm^{-2} atm^{-1}$ respectively. A complete set of harmonic frequencies and first-order anharmonic constants has been obtained. The effects of Darling-Dennison resonance are surprisingly weak.