Electron temperature T of a PIE plasma as a function of the pressure form of the ionisation parameter Ξ. The curves are calculated using the Cloudy, SPEX, and XSTAR photoionisation codes, shown in blue, red, and green, respectively. The calculations are carried out for the four different SEDs of Fig. 1: AGN1 (top panel in solid line), AGN2 (top panel in dashed line), PL (bottom panel in solid line), and BB (bottom panel in dashed line).