The refractive indices of 509 oxides and 55 fluorides were analyzed using two forms of a one-term Sellmeier equation: ͑1͒ 1/(n 2 Ϫ1)ϭϪA/ 2 ϩB, where A, the slope of the plot of (n 2 Ϫ1) Ϫ1 versus Ϫ2 in units of 10 Ϫ16 m 2 , gives a measure of dispersion and B, the intercept of the plot at ϭϱ, gives n ϱ ϭ(1ϩ1/B) 1/2 and ͑2͒ n 2 Ϫ1ϭE d E o /(E o 2 Ϫ(ប) 2), where បϭthe photon energy, E o ϭthe average single oscillator ͑Sellmeier͒ energy gap, and E d ϭthe average oscillator strength, which measures the strength of interband optical transitions. Form ͑1͒ was used to calculate n at ϭ589.3 nm (n D) and n at ϭϱ (n ϱ), and the dispersion constant A. The total mean polarizabilility for each compound was calculated using the Lorenz-Lorentz equation: ␣ e ϭ3/4 ͓(V m) (n ϱ 2 Ϫ1)/(n ϱ 2 ϩ2)], where V m is the molar volume in Å 3. Provided for each compound are: n D , n ϱ , V m , ͗␣ e ͘, ͗A͘, ͗B͘, ͗E d ͘, ͗E o ͘, the literature reference, the method of measurement of n and estimated errors in n. Results obtained by prism, infrared reflectivity, ellipsometry, and interference methods are compared. Consistency of dispersion values among like compounds and structural families is used to evaluate the accuracy of refractive index data. Dispersion values range from 40 to 260ϫ10 Ϫ16 m 2 with the majority of values in the range of 60-100ϫ10 Ϫ16 m 2. High dispersion is associated with s 2 , p 6 , d 10 , and transition metal ions, H 2 O, and crystalline hydrates, whereas normal dispersion values are found in borates, aluminates, gallates, silicates, germanates, phosphates, and sulfates not containing H 2 O or any of the above ions. Exceptionally high dispersion is observed in liquid H
