Radial and vertical diffusion coefficients with respect to Stokes number for runs SI41-4-4-d and SI30-4-4-d. We doubled the box size to 0.4 × 0.4 H_g compared to the simulations in Fig. 23. Compared to the smaller box, both D_x and D_z converge to approximately the same values for each Stokes number. The exception seen in curve D_z,30 at intermediate Stokes numbers is likely a consequence of the fluctuations seen in their particle scale height in the smaller box (see Fig. 11). The diffusion coefficients corresponding to species that do not saturate within the simulation time are marked with a cross.