Steady-state ionization fraction, x_e (n_e is defined by Eq. (24)), for the fiducial model. Panel a: mid-plane ionization fraction as a function of radius. The gray shaded area corresponds to the radial locations within the mid-plane dead zone. Panel b: vertical profiles for the ionization fraction at the same radial locations as in Fig. 3. The solid black line corresponds to r = 1 au. The solid red line corresponds to r = 23⁻ au. The solid blue line corresponds to r = 23⁺ au. The solid green line corresponds to r = 80 au.