Factor group splitting and dispersion on internal vibrational modes: A qualitative discussion

Abstract

Factor group splittings, of common occurrence in the infrared and Raman spectra of crystals, and dispersion, usually encountered in discussions of lattice modes, are shown to be closely related phenomena. Their relationship is elucidated by a model comprising a linear array of four vibrating units. A correlation between this and a similar two vibrator model indicates a method by which, in favorable cases, dispersion and mode change contributions to factor group splittings may be separately measured by conventional vibrational spectroscopies.