Effect of Temperature on the Intensity of X-rays Diffusely Scattered from Rocksalt

P. Debye has predicted that x-rays diffusely scattered from simple cubic crystals should decrease in intensity by a factor ($1-e^{-M}$) as the temperature decreases. $M$ is a quantity depending on the characteristics of the crystal, wave-length of the x-rays used, and the angle of scattering. Later, Waller's modification of the Debye factor, namely, that the exponent should be $-2M$, enjoyed some experimental success in regular reflection. Quite recently, Jauncey and Harvey have announced an entirely new formula (in which diffuse scattering and regular reflection are shown to be complementary) for predicting the change in intensity of diffuse scattering with temperature, from the known temperature effect on atomic structure factors.