Some investigations in the theory of open-shell ions: Part IV. the basis of intensity theory

The basis of the theory of electric dipole intensities in centrosymmetric ions is critically examined. It is shown that the physical assumptions of one current version [3, 4, 5] of this theory are mathematically inconsistent and the necessary revision of the theory is given. It is also pointed out that excitations from odd parity filled shells into the d shell should give a significant, and usually negative, contribution to the intensities.