Upper left panel to lower left panel: 3D−1D abundance corrections for fictitious Fe i lines and Fe ii lines with excitation potential χ = 0 eV and χ = 2 eV at 3000 Å, 4000 Å and 5000 Å, computed for the 3D and 1D models with  [Fe/H]  = −3.0, including coherent scattering (black) and treating scattering as absorption (gray). The 1D calculations assume microturbulent broadening with ξ = 2.0 km s^-1. Lower right panel: abundance corrections for typical CH, NH and OH lines for the same models. Note that feedback of the 3D abundance corrections on the molecular equilibrium is not taken into account (see text).