Notes. The table lists: wavelengths in air λ_air; electronic configurations and spectroscopic terms of the lower and upper states, with excitation energies χ_low and χ_up ; oscillator strengths f; natural broadening coefficients γ_rad. (FWHM in angular frequency units); and ABO broadening cross-sections σ_H at reference velocity v = 10⁴ m s⁻¹ and exponents α_H, such that the cross-section is proportional to v^−α (Anstee & O’Mara 1995). Data sources are the same as used to construct the non-LTE model atom (Sect. 2.4); in particular, the transition probabilities were drawn from Tachiev & Froese Fischer (2002).