Best fit of the dimensionless bulk thermal conductivity as a function of coordination number Z and porosity ϕ. Panel (a) shows the behavior of the dimensionless function F(Z, ϕ) with respect to Z along constant-ϕ lines. The simulation results (filled circles) are fitted with the decoupled power-law Equation (9) (solid lines). Panel (b) is a similar plot along constant-Z lines, which are shown with different colored circles (simulations) and lines (model fit). We also compare our results with the same normalized bulk thermal conductivity from S. Arakawa et al. (2019) (dashed–dotted black line) and N. Sakatani et al. (2017) (dashed brown line). Panel (c) compares the decoupled power-law model fit with dimensionless conductivity from the simulations. The black dotted line here represents the ideal fit. Note that the error bars in the three panels represent one standard deviation on the parameters.