Quantum assignments and intensity measures for methane between 1100 and 1800 per cm - A comparison between theory and experiment

The paper analyzes line positions and absolute line strengths of Blatherwick et al. (1979), based on moderately high resolution spectra of methane between 1100 and 1800 per cm, obtained using the Fourier transform spectrometer and the multiple-pass cold cell at the NASA Ames Research Center. Hamiltonian models are used to calculate theoretical relative line strengths, which, in combination with measured line strengths, yield integrated band strengths for the fundamentals v2 and v4. Ratios of calculated intensities to experimental intensities are analyzed, and the systematic deviations in the P- and R-branches of the v2 band are found to be represented by a Herman-Wallis type factor for Coriolis interactions. An analysis of ratios of calculated to experimental intensities of the v4 band yields a small correction to the Herman-Wallis factor.