H-TF5 by CDGM

$$n(\lambda) = \sqrt{1 + \frac{1.55857\,\lambda^2}{\lambda^2 - 0.0110563} + \frac{0.109732\,\lambda^2}{\lambda^2 - 0.0544047} + \frac{1.10775\,\lambda^2}{\lambda^2 - 88.3222}}$$

$$\frac{dn}{dT} = \frac{n_0^2 - 1}{2\,n_0}\left[1.61 \times 10^{-6} + 2(1.46 \times 10^{-8})\,\Delta T + 3(-3.13 \times 10^{-11})\,\Delta T^2 + \frac{6.67 \times 10^{-7} + 2(7.58 \times 10^{-10})\,\Delta T}{\lambda - 0.241}\right] \Delta T = T - T_0, \quad T_0 = 20\,°\text{C}$$