Ewald's dynamical theory of diffraction for a defect crystal

The paper is based on the Ewald's approach to the problem of interaction of an electromagnetic wave with a coulomb crystal lattice. Born's formalism of the crystal dynamics is used. Defects of the lattice modify the dynamical matrix of the crystal which can be simply inverted in a case of a small defect density. The final formula describes the distribution of the scattered intensity of the incident light wave as a function of the defect configuration. The possibility of the extension of the method to the Laue theory is briefly discussed.