Collision-induced rototranslational spectra ofH2-He: Accounting for the anisotropic interaction

In a previous paper [G. Birnbaum et al., Phys. Rev. A 29, 595 (1984)] the collision-induced rototranslational absorption spectra of ${\mathrm{H}}_2$-He were computed from first principles, with the assumption of isotropic interaction. Here, we study the effects of the anisotropy on the basis of a distorted-wave approximation. Computed spectral intensities and shapes of the rotational lines differ from the previous results by less than the numerical uncertainties of the computations (∼1%), except in the far wings where intensities are increasingly greater than comparable results based on isotropic interaction.