On the selflocalization of deep excitons in valent crystals

It is shown that in the case of exciton selflocalization the appearing deformation turns to be enongh for ejection one of the atoms of the excited bonding into the interstitial, and localization is energetically advantageous. Calculated is the crystal deformation caused by the repulsive force between the nearest atoms as well as by the field of the quadrupole momentum appearing during excitation of this bonding. From the solution of the dynamic problem on the crystal atom motion under the effect of the immediately originated repulsive force it follows that the displacements approximately twice exceed the equilibrium in half of the average oscillation period of optical phonons and it can result in formation of interstitial vacancy defect