Comment on "Atomic structure and excitation cross section by electron impact of tungsten ions, W$^{38+}$" by El-Maaref et al [J. Phys. B 52(2019) 065202]

TL;DR

This paper critically examines and disputes the accuracy of recent computational results on tungsten ion properties, highlighting significant discrepancies and errors in prior calculations using multiple atomic physics codes.

Contribution

It provides a detailed critique demonstrating that the previously reported energy levels and collision strengths are incorrect and unreliable.

Findings

Previous results contain errors and discrepancies.

Discrepancies between different computational codes are significant.

The reported data cannot be trusted for scientific use.

Abstract

Recently, El-Maaref {\it et al}\, [J. Phys. B 52(2019) 065202] have reported results for energy levels, radiative rates and collision strengths ($\Omega$) for some transitions of Kr-like W~XXXIX. For the calculations of these parameters they have adopted several codes, including GRASP, DARC and FAC. For energy levels they have shown discrepancies of up to 1.64~Ryd between the GRASP and FAC calculations, whereas for $\Omega$ the differences between the DARC and FAC results are over an order of magnitude for a few transitions. In addition, for several transitions there is an anomaly in the behaviour of $\Omega$ between the two sets of calculations. In this comment, we demonstrate that their results from both codes are incorrect, and hence cannot be relied upon.