Fully resolved line to illustrate the magnitude of intensity increase of the weak components. Theoretical relative intensities calculated following Eq. (3) are given as arrows; the arrows are normalised to the strongest hfs component: transition from 9 043.14 cm^-1, J = 5/2 − → 20 837.98 cm^-1, J = 5/2 at λ_air = 847.596 nm or σ_vac = 11   794.84 cm^-1.