In Chap.  11 , we introduced the dynamic multislice theory that fully incorporates elastic scattering of electrons before and after inelastic excitations. The theory can, in principle, be applied to any inelastic excitation and the possible multiple scattering effects in crystals containing defects. Large amounts of calculations are usually required to include dynamic scattering of electrons after inelastic scattering, because the excitation of each state and the subsequent diffraction of the electron associated with this excitation must be calculated individually due to incoherence. The major obstacle to this approach is the involvement of many crystal excited states.