Different shapes of internal mixing profiles. Grey marks the convective core, blue the overshooting region, and green the extra diffusive mixing in the radiative envelope. Panels a-c have been zoomed in on the near core region, while panel d shows the mixing profile from the centre to the surface of the star. In panels a and b the extra diffusive mixing in the radiative envelope has been set constant. Panel a: step overshoot. Panel b: exponential overshooting. Panel c: extended exponential overshoot where the extension replaces the constant diffusive envelope mixing in panels a and b. Panel d: exponential overshoot coupled to an extra diffusive mixing profile D_ext(r) from Rogers & McElwaine (2017) instead of a constant mixing (green dashed line).