Radiative accelerations vs. log T at mid-MS computed with OP data (thick black lines) and the SVP2020 and SVP2004 methods (red and blue lines, respectively) for a chemically homogeneous 1.5 M_⊙ model. The dotted lines denote the local gravity (in absolute values). The vertical lines show the location of the bottom of the H and He convective zones (dashed and dash-dotted lines, respectively). The grey bar near the centre of each panel illustrates the maximum acceptable difference in the g_rad (see the main text). The gap in the OP curve for Na corresponds to negative values (not shown).