Table 1: Non-LTE model atoms.

Ion	Source
H	Przybilla & Butler (2004a)
He I	Husfeld et al. (1989), with updated atomic data
C I/II	Przybilla et al. (2001b)
N I/II	Przybilla & Butler (2001)
O I/II	Przybilla et al. (2000) combined with Becker &
	Butler (1988), the latter with updated atomic data
Mg I/II	Przybilla et al. (2001a)
S II/III	Vrancken et al. (1996), with updated atomic data
Ti II	Becker (1998)
Fe II	Becker (1998)