Abundance of Fe per spectrum obtained in this study compared with the one from the literature adopted for the determination of fundamental T_eff and logg in Soubiran et al. (2024) as a function of T_eff (fundamental value). The two panels and the different colours show the values from the different radiative transfer codes. Some outliers discussed in the text are indicated (the MOOG value of HIP 8837 is outside of the y-axis limits at ∼ 1.3).