Difference, for the same orders as Fig. 5, of the wavelength solution from the laser frequency comb and that from the thorium, i.e c₀ × (λ_Th − λ_LFC)∕λ_LFC, where c₀ is the speed of light in vacuum, for both the standard (green) and new (red) thorium solutions. The new thorium wavelength solutions match the laser frequency comb solutions much more closely. Especially, we can see that there are “jumps” on the green curves, while the red curves are continuous. We note that the laser solutions are fifth-order polynomials while the thorium solutions are third-order polynomials.