Relative number of the Voigt lines (gray bar) (as well as that of Gauss lines; light gray bar) against the total number of lines in the reference case (δ_voigt = δ_crit = 0). Also, relative errors of the Rosseland (triangle) and Planck (square) mean opacity as well as of the monochromatic absorption coefficient (filled circle) are plotted. The CE abundance data used here are taken from the first layer of a demo output produced by FASTCHEM, chem_output_agb_stellar_wind.dat. The asterisk in the upper panel indicates a run that employs HITRAN’s dynamic strength cutoff, instead of δ_crit.