NLTE departure coefficients b₂ and b₃ (see Sect. 3.3) calculated with RH (Rutten & Uitenbroek 2012, Fig. 10) and NESSY for the FCHHT-B solar atmosphere model (Fontenla et al. 2009). NOLBKG curve is the default calculation with the NLTE block of NESSY (see Fig. 8, left panel) without accounting for the effect of line blanketing. LBKG curve is the output of NESSY NLTE block taking into account the effect of blanketing by all lines within 100−1000 nm wavelength range. LOPA is the “low opacity” curve not taking into account the effect of line blanketing and corresponding to V_dop = 2000 km s^-1 when values are 400 times larger than those of for km s^-1.