A simple formula for the fundamental optical absorption of alkali halide melts

Significant similarities — with respect to absorption of ultraviolet — between the crystalline and liquid phases of the alkali halides are considered. It is shown that a simple formula which emerged from an earlier application of local electron transfer concepts to the fundamental absorption of the alkali halide crystals appears to apply equally well (i.e. within experimental error) to their melts. This formula fits the observations relating to the fundamental absorption of five molten alkali halides and yields predictions for all the others — which will, it is hoped, stimulate experimental activity.