Evolution of planetary surface radius and total radius (including the atmosphere, i.e. the 10 mbar contour) of (a) Case 1c, (b) Case 9c. Lefty-axis shows the radius R (km) and right y-axis shows the difference relative to the planetary radius with a fully molten mantle ΔR (%) (i.e. relative to the initial condition). Vertical dotted lines show the times at which the interior reaches a global melt fraction of ϕ_g = 0.75, 0.3, 0.1, and 0.01. (c) Mean molar mass of the atmosphere.