New model of collision-induced infrared absorption spectra of H \u3c inf\u3e 2 He pairs in the 2-2.5 μm range at temperatures from 20 to 300 K: An update

A revised numerical method to calculate the collision-induced absorption rotovibrational (RV CIA) spectra of H2He pairs in the fundamental band of hydrogen, at temperatures from 20 to 300 K is presented. The paper corrects few inaccuracies which exist in the previous modeling of the H2He absorption in this frequency range. New computations account for the previously neglected J-dependence of the vibrational matrix elements of the induced dipoles. Model spectra are presented which reproduce closely the latest quantum mechanical results and are found to agree with most experimental CIA coefficients of H2He to within a few percent. The numerical model uses simple analytical model lineshapes and can generate the RV CIA spectra of H2He extremely efficiently. A FORTRAN program, H2HE01, utilizing the described method is available upon request from the author. This work is of interest for the modeling of the atmospheres of the outer planets in the near-infrared region of the spectrum. © 1992