Normalized spectra computed with only one line specy (all atoms or individual molecules) included in the synthesis. This figure illustrates the line blocking by different species for metal-rich stars with solar α-enrichment ([M/H] = +0.5 and [α/Fe] = 0.0). Examples are shown for a solar-type star (T_eff = 5750 K and log(g) = 4.5; top left panel), a cool dwarf star (T_eff = 4250 K & log(g) = 4.5; top right panel), a very cool dwarf star (T_eff = 3000 K & log(g) = 4.5; bottom left panel), and a cool giant star (T_eff = 4250 K, log(g) = 2.0; bottom right panel). To ease the comparison, molecules are grouped with respect to their carbon-rich (C₂, CN, and CH) or α-rich (TiO, ZrO, MgH, CaH, SiH, and OH) nature.