Experimental tests of the general formula for the integrated intensity of a real crystal

The new formula for the integrated intensity of a real crystal has been tested experimentally with small crystal spheres of hambergite and of α quartz, and Mo Kα as well as Cu Kα radiation. Although both materials show very large extinction effects, excellent agreement is obtained between theory and experiment. Discrepancies between predicted and observed integrated intensities seem to be due to inadequately known atomic scattering powers and to experimental errors rather than to a failure of the theoretical formula. The mean radius of the perfect crystal domain was found to be 1.98 × 10⁻⁴ cm for the hambergite sphere and 0.47 × 10⁻⁴ cm for the quartz sphere.