Structural diagram of the coupling between the interior structure model and the atmosphere model. T_base is the temperature at the bottom of the steam atmosphere in radiative-convective equilibrium. z and M_atm denote the atmospheric thickness and mass, respectively. R_bulk and M_bulk correspond to the planet bulk radius and mass, respectively. R_guess refers to the initial guess of the bulk radius, while R_interior is the output bulk radius of the interior structure model in each iteration.