Analytic approximation to incoherently scattered X-ray intensities

The theoretically calculated incoherently scattered X-ray intensities of Cromer & Mann [J. Chem. Phys. (1967). 47, 1892-1893] and Cromer [J. Chem. Phys. (1969). 50, 4857-4859] for the elements 2 to 95 and 102 have been fitted to an analytic function. The coefficients of fit are tabulated and the accuracy of the fitting is discussed. The accuracy is very good for sin θ/λ ≤ 1.5 Å-1.