Coupled-cluster single-double calculations of the relativistic energy shifts in C IV, Na I, Mg II, Al III, Si IV, Ca II and Zn II

TL;DR

This paper employs a relativistic coupled-cluster single-double method to accurately calculate how strong electric dipole transition frequencies in various atoms and ions depend on the fine-structure constant, aiding in the search for its variation.

Contribution

It introduces more accurate calculations of relativistic energy shifts in monovalent atoms and ions related to the fine-structure constant using the coupled-cluster single-double method.

Findings

Results agree with previous calculations

Calculations are more accurate than prior work

Supports the search for variations in the fine-structure constant

Abstract

The relativistic coupled-cluster single-double method is used to calculate the dependence of frequencies of strong $E1$-transitions in many monovalent atoms and ions on the fine-structure constant $\alpha$. These transitions are used in the search for manifestations of the variation of the fine-structure constant in quasar absorption spectra. Results of the present calculations are in good agreement with previous calculations but are more accurate.