A wide variety of microwave transitions within the υ9 = 1 vibrational state of nitric acid have been measured in the millimeter/submillimeter region. Torsional splittings on the order of 2.5 MHz have been observed and are due to the fact that the ν9 mode is a large amplitude torsional-type motion. Using an internal-axis-method-like formalism, an approach was developed to account for the effects of this large amplitude motion and was afterward applied to the analysis of the microwave frequencies. The model fits the data to within experimental accuracy, and provides quantitative predictions of relative transition intensities.
ASJC Scopus subject areas
- Atomic and Molecular Physics, and Optics
- Physical and Theoretical Chemistry