Radial diffusion coefficients estimated from 40 000 tracer particles over 2.5 10⁶ s for the models with different initial values of f_ov. The lines have been shifted such that the radial position of the structural boundary matches for all the simulations. The dotted vertical lines indicate the position of R_chem in each run. The red dashed line shows D according to Eq. (11) with f_ov = 0.01