'Dirac-Fock plus core-polarization' calculations of E1 transitions in the francium isoelectronic sequence

Some E1 transitions in the francium isoelectronic sequence are computed in the 'Dirac-Fock + core-polarization' approximation, where core-valence electron correlation is treated in a semiclassical core-polarization picture. The obtained ionization energies and oscillator strengths are tested versus very accurate many-body perturbation treatment (MBPT) theoretical results published recently as well as versus available experimental data. The role of core-valence correlation ( core polarization) is carefully studied for both ionization energies and oscillator strengths along the spectral series and isoelectronic sequence. Profound anomalies in oscillator strength fine structure components for the principal series of neutral francium are predicted and await experimental confirmation.