Energy levels and radiative rates for transitions in Cr-like Co IV and Ni V

TL;DR

This paper presents calculated energy levels and radiative rates for transitions in Cr-like Co IV and Ni V using multiple atomic structure codes, providing new data where none previously existed.

Contribution

The study offers the first comprehensive set of radiative rates and energy levels for Co IV and Ni V, using QRHF, GRASP, and FAC methods for comparison.

Findings

Calculated energies agree closely with NIST data for most levels.

Radiative rates for E1, E2, and M1 transitions are provided.

Lifetimes of levels are reported, filling a data gap.

Abstract

We report calculations of energy levels and radiative rates ($A$-values) for transitions in Cr-like Co IV and Ni V. The quasi-relativistic Hartree-Fock (QRHF) code is adopted for calculating the data although GRASP (general-purpose relativistic atomic structure package) and flexible atomic code (FAC) have also been employed for comparison purposes. No radiative rates are available in the literature to compare with our results, but our calculated energies are in close agreement with those compiled by NIST for a majority of the levels. However, there are discrepancies for a few levels of up to 3\%. The $A$-values are listed for all significantly contributing E1, E2 and M1 transitions, and the corresponding lifetimes reported, although unfortunately no previous theoretical or experimental results exist to compare with our data.