A total of 3155 vibration-rotation line positions providing accurate information on all known vibration-rotation states up to 3000 cm-1 in 12C2H2 were gathered from the literature. An additional 966 lines were assigned on new spectra. The full data set was simultaneously fitted using an appropriate Hamiltonian, with 85 refined parameters. A dimensionless standard deviation equal to 0.86, accounting for 92% of the lines, was achieved. The vibrational transition dipole moment of the 5 = 1 4 = 1 band observed in the far-infrared was estimated to be |μ5←4| = 0.55 D with 20% accuracy, from absolute intensity measurements for a few Q-branch lines.
Robert, S., Herman, M., Vander Auwera, J., Di Lonardo, G., Fusina, L., Blanquet, G., ... Fayt, A. (2007). The bending vibrations in 12C2H2: global vibration-rotation analysis: Global vibration-rotation analysis. Molecular physics, 105(5-7), 559-568. https://doi.org/10.1080/00268970601099261