RELATIVISTIC MANY-BODY METHODOLOGY OF ELECTRIC-DIPOLE OSCILLATOR-STRENGTHS WITH APPLICATION TO TL+ 6S2-]6S6P

A systematic way of simultaneously handling relativistic and many-body effects for electric dipole transition probabilities is introduced. Relativistic many-body wave functions are generated using a relativistic configuration-interaction (RCI) approach, where the virtual space is represented by screened hydrogenic functions whose effective charges are determined during the RCI process. It is shown that the number of parents that must be kept in a first-order wave function may be minimized, using a procedure called reduce. The relativistic form of the first-order theory of oscillator strengths is used to determine which configurations are crucial. Application is made to the Tl+ 6s2 6s6p 1,3P1 transitions for which both nonorthonormality and core excitation effects are found to be crucial. For the allowed transition, our results (length and velocity) are in excellent agreement with experiment. © 1990 The American Physical Society.