Relativistic oscillator strengths and excitation energies for the ns²¹S₀-nsnp³P₁,¹P₁transitions. I. The mercury isoelectronic sequence

Relativistic excitation energies and oscillator strengths are computed for both the resonance transition 6s 2 1 S 0 -6s6p 1 P 1 and the intercombination line 6s 2 1 S 0 -6s6p 3 P 1 in the mercury isoelectronic sequence. In the authors' approach to the correlation problem, limited relativistic configuration mixing which represents, intravalence correlation is combined with a polarisation model which accounts for valence-core correlation. Systematic trends along the sequence are discussed both the oscillator strengths and for contributions of intravalence and valence-core electron correlation. Theoretical ionisation potentials, corrected for relativistic and core polarisation effects, are predicted for 1 S 0 , 3 P 1 and 1 P 1 states in the Po V, At VI and Rn VII spectra of the mercury sequence as well as for the 2 S 1/2 ground states in the Po VI, At VII and Rn VIII spectra of the gold isoelectronic sequence.