Resolving a discrepancy between experimental and theoretical lifetimes in atomic negative ions

Research output: Contribution to journalArticle


A recent measurement of the lifetime of the excited 3p5 state in the S- negative ion, which is dominated by a forbidden magnetic dipole transition to the 2 P3/ 2 ground state, reveals a discrepancy with earlier theoretical predictions. To investigate this we have performed systematic and large-scale multiconfiguration Dirac-Hartree-Fock calculations for this system. After including a careful treatment of correlation and relativistic effects, we predict a well-converged value for this lifetime, with an uncertainty considerably less than 1%, thereby removing the apparent conflict between theory and experiment. We also show that this result corresponds to the non-relativistic limit in the LS coupling approximation for the magnetic dipole transition within this 2 P term. In addition we demonstrate the usefulness of the latter approach for 2 P transitions in O-, Se- and Te-, as well as for analogous M1 transitions within 2 D terms in Ni- and Pt- ions.


Research areas and keywords

Subject classification (UKÄ) – MANDATORY

  • Atom and Molecular Physics and Optics


  • atomic structure, bound states, forbidden transitions, lifetimes, negative ions
Original languageEnglish
Article number025001
JournalJournal of Physics B: Atomic, Molecular and Optical Physics
Issue number2
Publication statusPublished - 2017 Jan 28
Publication categoryResearch