Effect of the coefficient diffusion on the final [Mg/Fe] dispersion of the Sextans (r= 6) models. Each panel corresponds to a different coefficient. The dispersion is compared to the fiducial model run with the smooth metallicity scheme. As in Figs. 10 and 11, the black curves show the 1σ dispersion. For comparison, observations at low metallicity ([ Mg / Fe ] < −2.5) of individual stars taken from Fig. 1 are shown in yellow. In each [Mg/Fe] vs. [Fe/H] plots, the shaded region corresponds to the 1σ dispersion around the mean. Individual measurements are shown with small stars.