Left panel: time evolution of the abundances of PAH (grey) and PAH⁻ (black) normalized to the total hydrogen number density (i.e. 2 × 10⁴ cm^-3). We compare the WH2008 electron attachment rates (solid) with those obtained using instead. The anthracene rates (long-dashed), the perylene rates (dashed), and the coronene rate (dotted). The lines that represent the PAH densities overlap, except those from WH2008. Right panel: electron number density time evolution as given by the same set of models. The two panels have different vertical scales.