Frequency dependent electron collisional widths for opacity calculations

It is shown that theoretical Rosseland mean opacities are sensitive to spectral line shape models. Due to computational constraints, however, opacity codes typically use Voigt or Lorentz profiles. Both of these profiles have an incorrect far wing behavior that can significantly overestimate the photon absorption. A new line profile is proposed, based on second-order line broadening theory, which is both more physical and relatively fast to compute.