The direction and intensity of secondary beams depend on the structure of the object scattering X-rays. Crystal is a natural three-dimensional diffraction grating for X-rays, because the wavelength of X-ray radiation is of the same order as the distance between the scattering centres (atoms) in the crystal (~1Å).

The phenomenon of X-ray diffraction is utilised in such techniques as X-ray diffraction and X-ray powder diffraction. The X-ray diffraction technique is based on the phenomenon of X-ray diffraction on a three-dimensional crystal lattice of a single crystal. The technique is used to solve the atomic structure of matter, which includes the space group of the unit cell, its size and shape, and the group of crystal symmetry. X-ray powder diffraction is a technique of investigating the structural characteristics of a material by means of X-ray diffraction by powder or polycrystalline sample of the material. This study yields the scattered light intensity as a function of scattering angle. The technique provides the qualitative and semi-quantitative composition of the sample, the unit cell parameters of the sample, material texture, the size of the crystallites (coherent scattering region) of the polycrystalline sample.