Microscopic Theory of Band and Local States in Ionic Crystals

The theory of band and local states of electrons in ionic crystals with due regard for interelectronic interaction and with some approximation to the interelectron correlation was proposed [1]. It is developed for NaCl crystals having one excess electron. The law of dispersion and the wave functions of a band electron are defined here. The minimum E ( k ) is at k = 0 and the effective mass is equal to 0.624 m , where m is the mass of the free electron. The energy and the radius of the polaron in strong‐bond approximation practically coincide with the results of the macrotheory [2]. This gives an opportunity to apply its methods and the approximation of intermediate and weak bonds, for at \documentclass{article}\pagestyle{empty}\begin{document}$ \mu /m = 0.624,\,\alpha = 3.95\sqrt{2\,.} \left[3 \right] $\end{document} . The calculated potential of deformation and the acoustic mobility are in good agreement with the results of experiments [4] in a temperature range of 30 to 200°K.