The impact of the blending lines in the Li I λ670.8 nm region on the resulting 3D NLTE corrections. The best fitting 1D LTE spectrum (blue continuous line) is superimposed on the 3D NLTE spectrum (black dotted line) computed for T_eff = 5870 K, log ℊ = 4.5, [Fe/H] = 0, A(Li)_3DNLTE = 2.0, ⁶Li/⁷Li_3DNLTE = 5% and representing the “observation”. The synthetic spectra are computed adopting only the Li I doublet including hyperfine structure (line list K95, upper panel), and the line list G09 (lower panel), which includes also other atomic blends. The right y-axis gives the scale of the residuals (blue dashed line). We measure A(Li) = 1.92 and ⁶Li/⁷Li = 6.1% for line list K95, and A(Li) = 1.92 and ⁶Li/⁷Li = 5.4% in case of line list G09.