Chemical abundances derived from optical emission lines in our sample of AGN. (a) Comparison between the chemical abundances derived with the calibration from Flury & Moran (2020; y-axis), denoted as FM20, and HCM (x-axis). (b) Comparison between the chemical abundances derived from the calibration from Carvalho et al. (2020; y-axis), denoted as FM20, with HCM (x-axis). For all plots we present Seyferts as blue circles, ULIRGs as green squares, LIRGs as magenta triangles, and LINERs as red stars. The offsets are given using the median value (dashed line) and RMSE (dot-dashed lines). Bottom plots show the residuals from the offset and their distribution in a histogram (bottom-right plot).