Breit and QED effects on the 3d9 D3/2 2 →2D5/2 transition energy in Co-like ions

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The multiconfiguration Dirac-Hartree-Fock theory is used to calculate the 3d9D3/22→2D5/2 transition energy for Co-like ions with Z=28-100. We investigate how electron correlation, frequency-independent and -dependent Breit interactions, as well as QED corrections vary along the sequence. The well-understood frequency-independent Breit contribution has the largest contribution for all ions. Among the corrections to this, correlation decreases rapidly with Z, the frequency-dependent Breit contribution is important especially for high-Z ions, and the self-energy contribution to the QED becomes the largest correction already for Z>50. We evaluate and compare results for the Self-energy in three different approximations, (i) the approach implemented in the grasp2k package, (ii) the method based on Welton's concept and (iii) a model operator approach recently developed by Shabaev and coworkers. Through comparison with experimental values, it seems that the third set of results have the best agreement with experiments, but the difference from experiments for high-Z ions, is around 0.03%-0.04%, and therefore our results are outside the error bars of the experiments.


  • R. Si
  • X. L. Guo
  • T. Brage
  • C. Y. Chen
  • R. Hutton
  • C. Froese Fischer
External organisations
  • University of British Columbia
  • Second Military Medical University
  • Fudan University
Research areas and keywords

Subject classification (UKÄ) – MANDATORY

  • Physical Sciences
Original languageEnglish
Article number012504
JournalPhysical Review A
Issue number1
Publication statusPublished - 2018 Jul 13
Publication categoryResearch