Results for departure coefficients b_ with the logarithm of the optical depth at 500 nm, log τ₅₀₀, across a grid of MARCS model atmospheres. In the upper right corner of each panel T_eff/ log 𝑔 is given, and each panel shows plots for different metallicity [Fe/H] = 0, −1, −2, and −3. The thickest (purple) line shows 0, and the thinnest (orange) line shows -3. This grid does not include a model with T_eff/ log 𝑔/[Fe/H] = 7000/3.0/ − 1.