Distribution of coronene charge and hydrogenation state for three different values of G₀ and n_H. Coronene cations are plotted with dashed lines, and neutral coronene molecules have solid lines. Only the most abundant hydrogenation states are shown. The top graph has G₀ = 10^2.5 and n_H = 10^3.5 cm^-3, the middle graph G₀ = 10^3.0 and n_H = 10^3.5 cm^-3, and the bottom graph corresponds to G₀ = 10^2.5 and n_H = 10^4.5 cm^-3. The vertical line marks the location of the H/H₂ transition, where n(H) = 2·n(H₂).