EFFECT OF ELECTRON CORRELATION ON THE FORCED ELECTRIC-DIPOLE TRANSITION-PROBABILITIES IN FN SYSTEMS - GENERAL EFFECTIVE OPERATOR FORMULATION

A method for the investigation of the effects of electron correlation on the forced electric dipole transition probabilities between levels of the fn configuration is presented. The approach is based on double perturbation theory and on the application of effective operators. Effective operators describing the correlation effects are generated for various classes of perturbing configurations in terms of generalized unit tensor operators. A classification scheme for the possible operators is presented. In general, one- and two- particle operators are obtained. The latter do not appear in the standard Judd-Ofelt theory. One-particle operators dependent on unit tensor operators of odd rank are also new. The other one-particle operators are of the form considered in the Judd-Ofelt theory. However, the present results indicate that the interpretation of the empirical parameters of this theory should be modified to take into account electron correlation effects. © 1979 Taylor and Francis Ltd.