Measurements and calculations of Ar-broadening and -shifting parameters of water vapor transitions of ν1+ν2+ν3 band

- Measurements of H2O absorption spectra, perturbed by Ar are performed.
- Data on lines broadening and shift coefficients for ν1+ν2+ν3 band of H2O are presented.
- The parameters of the intermolecular potential for the H2O-Ar system are obtained.

The water vapor line broadening and shifting for 94 lines in the ν1+ν2+ν3 band induced by argon pressure are measured with Bruker IFS 125 HR FTIR spectrometer. The measurements were performed at room temperature, at the spectral resolution of 0.01 cm−1 and in a wide pressure range of Ar. The calculations of the broadening coefficients γ and δ were performed in the framework of the semi-classical method. The intermolecular potential was taken as the sum of pair potentials which, in turn, were modeled by the Lennard-Jones potentials. Optimal sets of potential parameters given the best discrepancy of measured broadening coefficients are found. The influence of the rotational dependence of an intermolecular potential and its repulsive part on the calculated coefficients γ and δ is discussed.