Resonance Transition Energies and Oscillator Strengths in Lutetium and Lawrencium

Abstract

The transition energies and oscillator strengths for $\mathrm{nd}^{2}D_{3/2}\ensuremath{-}(n+1)p^{2}P_{1/2,3/2}^{o}$ transitions in Lu ( $n\phantom{\rule{0ex}{0ex}}=\phantom{\rule{0ex}{0ex}}5$, $Z\phantom{\rule{0ex}{0ex}}=\phantom{\rule{0ex}{0ex}}71$) and Lr ( $n\phantom{\rule{0ex}{0ex}}=\phantom{\rule{0ex}{0ex}}6$, $Z\phantom{\rule{0ex}{0ex}}=\phantom{\rule{0ex}{0ex}}103$) were calculated with the multiconfiguration Dirac-Hartree-Fock method. The present study confirmed that the ground state of atomic Lr is $[\mathrm{Rn}]{5f}^{14}{7s}^{2}7p^{2}P_{1/2}^{o}$. The calculation for Lr required wave function expansions of more than 330 000 configuration states. In Lu, the transition energies, with Breit and QED corrections included, agree with experiment to within $126{\mathrm{cm}}^{\ensuremath{-}1}$. In lighter elements, core correlation is usually neglected but was found to be of extreme importance for these heavy elements, affecting the oscillator strengths by a factor of 3 and 2 in Lu and Lr, respectively.