Comparison between different input SEDs for CLOUDY photoionisation models. All models are normalised to their fluxes at 1 Ryd. The solid and dashed curves correspond to SEDs constructed from the parametric function in CLOUDY. The dash-dotted and dotted curves are SEDs constructed from observations of AGNs by Jin et al. (2012, 2017). The left edge and the right edge of the shaded region correspond to the ionisation potential of Fe⁰ and Fe⁺, respectively.