Comment on the Debye-Waller factors for incommensurate structures

We show that the method of calculations of the Debye-Waller factors for IC structures by J.D. Axe, Phys. Rev. (1971), B 21, 4181, is not applicable for such calculations. The set of variables, which should be used for such calculations, is the phase $\phi$ and the amplitude of the IC modulation, but not the real and imaginary parts of the complex IC modulation function.