Critique of the Pekar theory of the F‐center

A discussion is presented of the Pekar treatment of optical absorption and emission by the F‐center in alkali halides, in which the crystal is treated as a polarizable dielectric continuum. In some important respects this is the most successful theory yet developed; nevertheless it is shown to lead to very poor predictions of other observable quantities, and more important, to contain striking internal inconsistencies. These are pointed out and discussed. The theory is interpreted in a way which shows how, as it has been applied, it is essentially invariant with respect to the internal inconsistency as well as to a demonstrably false assumption on which it is based.