Abundance corrections for the 3838 Å, 5528 Å, 4571 Å, 5184 Å, and 8718 Å lines in four different atmospheric models and using modified model atoms as described in the text. The model parameters are given at the bottom left of each figure with T_eff/log g/[Fe/H]. The shaded region indicates the likely abundance of Mg for a normal star of given metallicity. The black circles show the calculated abundances; some lines have fewer points because the calculations with those parameters did not converge. Note that the model atoms shown in the 4571 Å line case differ from the others.