Key points are not available for this paper at this time.
The sudden death of Gerhard Dieke at the Aberdeen Summer School on phonons in 1965 robbed the scientific world of a dedicated solid state spectroscopist. Dieke was involved in the Manhattan Project as a spectroscopist studying the uranyl salts and this led him into a detailed study of the absorption and fluorescence spectra of the rare earths which commenced in 1953 and ended with his untimely death.
Donald W. Goodwin (Mon,) studied this question.