Line mixing effects in the v3 band of CH3F in helium: Experimental band shapes and ECS analysis
U.M.R. C.N.R.S. 6627, Université de Rennes I, Campus de Beaulieu,
35042 Rennes Cedex, France
2 Institute of Physics, St. Petersburg University, Peterhof, 198904 St. Petersburg, Russia
Published online: 15 June 1999
Line mixing effects have been studied in the band of perturbed by helium. Theoretical absorption coefficients are compared to FTIR measurements, which were made at room temperature for helium pressure from 1 atm up to 90 atm. The observed strong modifications with respect to additive Lorentzian contributions are explained by line coupling effects. The Infinite Order Sudden Approximation and the Energy Corrected Sudden Approximation are used in order to account for these effects. The latter gives better agreement: it rather successfully predicts the band shape and the linewidths.
PACS: 33.20.Ea – Infrared spectra / 33.70.-w – Intensities and shapes of molecular spectral lines and bands / 34.10.+x – General theories and models of atomic and molecular collisions and interactions (including statistical theories, transition state, stochastic and trajectory models, etc.)
© EDP Sciences, Società Italiana di Fisica, Springer-Verlag, 1999