Nd III transition 4f^{4 5}I₆–4f³(⁴I°)5d ³I°₇ at 21 615.679 cm⁻¹, slightly blended with an unclassified line at 21 616.058 cm⁻¹. Fits using asymmetric Voigt and normal Voigt profiles are shown in dashed and dotted lines, respectively, their residuals are shown in the lower plot and their fitted wavenumbers are shown by the vertical lines. The wavenumber uncertainty of the asymmetric Voigt fit ∆σ is shown in the zoomed section.