Absolute Infrared Transition Moments for Open Shell Diatomics from J Dependence of Transition Intensities: Application to OH

摘要

A general approach to the determination of the dipole moment function and of the absolute vibrational transition moments for diatomic molecules is presented. This method utilizes the variation of intensity with J within a vibrational transition, together with permanent dipole moment information, to extract the absolute transition moments. An essential feature of the model is its use of algebraic expressions for calculating vibration-rotation line intensities. These expressions can be rapidly evaluated in a least squares fit which determines the dipole moment function. This approach is general in that it is not limited to 1 sigma state molecules, nor to the simplest of Hund's case couplings of spin, orbital and mechanical angular momentum. It is successfully applied to the OH molecule which violates each of these restrictions. In the accompanying work we report experimental measurements of relative infrared absorption intensity measurements for OH v=0 to 1 transitions and the extraction of an experimental (r) using the approach presented here. Keywords: Absorption spectra, Herman Wallis effect; Reprints. (aw)