On the boundary conditions in crystal optics with spatial dispersion

The non-homogeneous boundary conditions in the theory of spatial dispersion are considered. It is shown that non-homogeneity in the boundary condition for polarization causes a discontinuity in the tangential components of the magnetic field at the boundary. Separate boundary conditions do not contradict the Energy Conservation Law only if they are connected in a certain way. The values of parameters introduced in the theory are obtained with the help of numerical methods. The theoretical spectra of reflectivity obtained with such parameters coincide with the experimental ones.