Isotope shifts and relativistic shifts of Cr II for study of alpha-variation in quasar absorption spectra

Abstract

We use the combination of configuration interaction and many-body perturbation theory method (CI+MBPT) to perform ab initio calculations the low-energy spectra of Cr II with high accuracy. It is found that second-order MBPT diagrams should be included in a consistent and complete way for the MBPT to improve the accuracy of calculations in this five-valence-electron system. This contrasts with previous ions with fewer valence electrons where it was found that single-valence-electron diagrams dominate the corrections. Isotope shifts and relativistic shifts (q-values) are calculated for use in astronomical determination of the fine-structure constant in quasar absorption spectra.

6 pages, 1 figure, 6 tables

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Cited by in corpus (10)

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• Optical spectroscopy of complex open 4$d$-shell ions Sn${}^{7+}$-Sn${}^{10+}$
• Laboratory atomic transition data for precise optical quasar absorption spectroscopy
• Precise limits on cosmological variability of the fine-structure constant with zinc and chromium quasar absorption lines
• Saturated configuration interaction calculations for five-valent Ta and Db
• Energy Level Structure of Sn${}^{3+}$ Ions
• Measuring chemical evolution and gravitational dependence of αusing ultraviolet Fe V and Ni V transitions in white-dwarf spectra
• Precision calculation of energy levels for four-valent Si I