Abstract:
The exchange e-h Coulomb scattering takes place with the annihilation and the creation
of the e-h pairs with the resultant electronic charges equal to zero. During the direct Coulomb
scattering the electron and a hole remain in the same energy bands interacting as a charged
particles. They have dipole-dipole interaction, when the interband dipole moments c v r − are
different from zero. It happens when the crystals have the dipole active optical quantum
transitions.