Individual values of [X/H] as a function of spectroscopic estimates of T_eff, derived from the analysis of the optical spectra (open symbols) and from the analysis of NIR spectra (red symbols). The symbols for the three stars for which we analysed GIARPS spectra are the same as in Fig. 3. All trends have Pearson correlation coefficients that are not significant at p < 0.1, apart from Cr II (see the text for details).