gf values for the O I λ7771 line. The results of all different model calculations are shown in increasing order of complexity from left to right. The values depicted are AUTOSTRUCTURE length (AUTOSS (L)) and velocity (AUTOSS (V)) gauges as circles and square points, respectively; MCDHF Babushkin (MCDHF (B)) and Coulomb (MCDHF (C)) gauges are shown with diamond and triangular points, respectively; HFR+CPOL is the horizonal long-dashed line; and R-matrix length (R-matrix(L)) and velocity (R-matrix(V)) gauges are shown with dot-dashed lines. The point with error bars at the right end of the plot depicts our recommended gf fvalue for the transitions and its estimated uncertainty.