Magnesium photoionization absorption coefficients per Mg atom [cm²] at 5000 K. The brown curve indicates the photoionization from the ground level, and is a hybrid of Verner et al. (1996) (outer-subshell contributions; yellow) and Verner & Yakovlev (1995) (inner-subshell contributions; cyan). Both the magenta and black thin curves indicate the photoionization from excited levels; the former is based on the Mathisen (1984) compilation, whereas the latter is based on TOPbase.