Theory of the fine structure of the UV absorption of heavy metal ions in the alkali halides

The energy level matrices associated with transitions of the type d 10 to d 9 s are constructed employing the strong crystal field formalism. The resulting expressions eliminate the difficulties of the formulation given by Knox (1963) at the expense of introducing additional parameters. Means of estimating these are described. Finally arguments are presented which show that the reported characteristics of the spectra attributed to Cu + ions in the potassium halides are consistent with the assignment of this ion to an interstitial position.