Mechanism of self-trapping of electron excitation in alkali-halide crystals

A dynamic method is used to calculate the equilibrium positions of ions near heavy and light homologous impurities for KCl:J and KJ:Cl crystals. The most probable sites of self-traps are shown.Lattice ralaxation near an excited anion is modeled. The localization of electron excitations (EE) in alkali-halide crystals is examined from the viewpointof the formation of a covalent bond between anions as a relust of their approach toward each other. The EE localization time is determined by the lifetime of local vibrations in the crystal near the excited anions (5-10^–13–10^–11 sec).Translated from Izvestiya Vysshikh Uchebnykh Zavedenii, Fizika, No. 1, pp. 35–38, January, 1986.