First-Order Intensity Perturbations for the Vibration–Rotation Lines of Asymmetric Rotor: Theory and Application

A general theoretical treatment of intensity perturbations is given for the vibration–rotation lines of asymmetric rotor. The nonlinear $\mathrm{XYX}$ molecules are specially treated, and for this case a new formula is derived for the correction $F$ factors of the intensities. A good agreement is obtained with other authors for the bands ${\nu }_1$ and ${\nu }_2$ of H₂O;, and new information is derived for the band ${\nu }_3$ of the same molecule.