Interior properties of a MESA model of the white dwarf G 29–38, as a function of density ρ. As expected, the scalings from a radiative envelope based on an ideal gas equation of state break down in the degenerate core (ρ ≳ 70 g cm⁻³), where electron degeneracy pressure dominates and P ∝ ρ^5/3 instead. RZ stands for radiative zone. The bottom right panel shows the atomic diffusion coefficients D_i (solid) and gravitational settling velocities U_set,i (dotted) of the accreted elements from MESA, together with the mass-weighted diffusivity of the mixture (black). The dashed orange lines show D ∝ T^5/2/ρ, as predicted by Equation (2) in M. Deal et al. (2026), and the fit ﹩{U}_{{\rm{set}}}={U}_{{\rm{mix}}}{(\rho /{\rho }_{0})}^{-2/3}﹩. Settling velocities are shown only above the depth reached by the accreted material after 50 kyr.