Notes. Oscillator strengths for Mg I lines come from Pehlivan Rhodin et al. (2017), with preference given to experimental values where available except for the 571 .1 nm line (theoretical value was adopted); for the 457.1 nm line, the theoretical value from Jönsson & Froese Fischer (1997) was used instead. As discussed in the text, the radiative transfer calculations assumed log gf = −5.397 for the 457.1 nm line, and log gf = −1.842 for the 571.1 nm. Oscillator strengths for the Mg II line comes from Froese Fischer et al. (2006) via NiST (Ralchenko & Kramida 2020). ABO broadening parameters (e.g. Barklem 2016a) obtained via interpolating extended tables at https://github.com/barklem/abo-cross with the value for the Mg I 473.0 nm line taken from the edge of the corresponding table.