ESTIMATES OF VIBRONIC COUPLING EFFECTS ON THE VISIBLE AND INFRARED SPECTRA OF $NO_{2}$ AND $C10_{2}$ MOLECULES

Abstract

It is found that if one assumes vibronic mixing of the $A^{-2}A_{2}$ and $X^{-2}B_{1}$ states of $C10_{2}$ by $\nu_{3}(b_{2})$, with a coupling constant of $1500 cm^{-1}$, observed vibrational levels in both states and some unusual transition probability observations can be modelled. The model is therefore applied also to the $A^{-2}B_{2}$ and $X^{-2}A_{1}$ states of $NO_{2}$, for which vibronic interaction has been suspected for the past 15 years. The coupling constant for $NO_{2}$ is $1000 cm^{-1}$. It is predicted that the unidentified $3^{2}_{0}$ band of the $A^{-2}B_{2-}X^{-2}A_{1}$ transition of $HO_{2}$ is seven times as strong as the ${3^{0}}_{2}$ band, and that it lies $2470 cm^{-1}$ above the (also unidentified) D-D band.