The refractive indices of 509 oxides and 55 fluorides were analyzed using two forms of a one-term Sellmeier equation: (1) 1/(n2−1) = −A/λ2+B, where A, the slope of the plot of (n2−1)−1 versus λ−2 in units of 10−16 m2, gives a measure of dispersion and B, the intercept of the plot at λ = ∞, gives n∞ = (1+1/B)1/2 and (2) n2−1 = EdEo/(Eo2−(ℏω)2), where ℏω = the photon energy, Eo = the average single oscillator (Sellmeier) energy gap, and Ed = the average oscillator strength, which measures the strength of interband optical transitions. Form (1) was used to calculate n at λ = 589.3 nm (nD) and n at λ = ∞ (n∞), and the dispersion constant A. The total mean polarizabilility for each compound was calculated using the Lorenz–Lorentz equation: αe = 3/4π [(Vm) (n∞2−1)/(n∞2+2)], where Vm is the molar volume in Å3. Provided for each compound are: nD, n∞, Vm, 〈αe〉, 〈A〉, 〈B〉, 〈Ed〉, 〈Eo〉, 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 260×10−16 m2 with the majority of values in the range of 60–100×10−16 m2. High dispersion is associated with s2, p6, d10, and transition metal ions, H2O, and crystalline hydrates, whereas normal dispersion values are found in borates, aluminates, gallates, silicates, germanates, phosphates, and sulfates not containing H2O or any of the above ions. Exceptionally high dispersion is observed in liquid H2O, Fe2O3, Y3Fe5O12, FeOOH, Fe2(SO4)3, UO2, Cu2O, V2O5, MgCrO4⋅7H2O, and Cs2Mg(CrO4)2⋅6H2O. © 2002 American Institute of Physics.
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