Best NLTE (continuous curve) and LTE (dotted curve) fits of the Mg i 5172 Å line in HD 122563 (bold dots). The NLTE calculations were performed with log A_Mg =  −6.95, while the LTE ones with a 0.02 dex higher value. Mg+H collisions are treated following BBSGF. Our theoretical flux profiles were convolved with a profile that combines instrumental broadening with a Gaussian profile and broadening by macroturbulence with a radial-tangential profile. The macroturbulence values are 4.7 km s^-1 for the NLTE and 3.8 km s^-1 for the LTE fits.