Diffraction by layer structures containing different kinds of layers and stacking faults

A description is given of a mathematical formalism which allows the study of diffraction by stacks which contain, simultaneously or not, (i) layers of different kinds, (ii) different translations or rotations between layers and (iii) different thicknesses. The formalism allows the calculation of intensities for all the hkl reflections or (h,k) reciprocal rods, and not just the 00l reflections. It accounts for an Sth-neighbour interaction (S≥1).