4S4D1D-4P21D INTERACTION IN THE ZN-I ISOELECTRONIC SEQUENCE

The importance of the interaction between 4s4d D1 and 4p2 D1 is studied in the Zn I isoelectronic sequence from Zn I to W XLV. Multiconfiguration Hartree-Fock calculations have been carried out for the two lowest D1 terms in this sequence and used to calculate gf values for the P1-D1 transitions. For the heavier elements relativistic effects are important and intermediate-coupling calculations of the gf values using multiconfiguration Dirac-Hartree-Fock transition energies have been carried out. Final gf values take into account relativistic effects in an approximate way, as well as core-polarization effects. The latter are found to be as important for the P1-D1 transitions as for the S1-P1 resonance transition even for high-ionization stages. The gf values for transitions from the lowest D1 terms were found to be small due to destructive interference. Little experimental data exist with which the present results can be compared. Furthermore, it is shown that much of the earlier experimental material concerning the D1 terms are in error. Comparison with a few very recent experimental investigations shows good agreement, however, and the present results point to the need for further experimental studies of this sequence, even towards the neutral end. © 1979 The American Physical Society.