The theory of x-ray diffraction for smectic-A films is presented. The effect of the smectic layer fluctuations and correlations and the molecular form factor on the interlayer structure and the x-ray diffraction pattern is discussed. The application of the presented theory to smectic-C, smectic-I, smectic-${\mathit{A}}_{\mathit{d}}$, and smectic-${\mathit{A}}_2$ films is suggested.

• Received 10 September 1990

DOI:https://doi.org/10.1103/PhysRevA.42.7511