Comment on "Collision strength and effective collision strength for Br~XXVII" by Goyal et al. [Can. J. Phys. 95 (2017) 1127]

TL;DR

This paper critically evaluates Goyal et al.'s 2017 study on collision strengths in Br~XXVII, revealing that their results are inconsistent and unreliable due to methodological issues.

Contribution

It provides a critical comment highlighting inaccuracies and unreliability in previous collision strength calculations for Br~XXVII.

Findings

Goyal et al.'s results are erratic and unreliable.

The reported collision strengths lack accuracy.

The critique questions the validity of the previous calculations.

Abstract

In a recent paper, Goyal et al. [Can. J. Phys. {\bf 95} (2017) 1127] have reported results for collision strengths ($\Omega$) and effective collision strengths ($\Upsilon$) for transitions among the lowest 52 levels of F-like Br~XXVII. For their calculations, they have adopted the Dirac atomic $R$-matrix code (DARC) and the flexible atomic code (FAC). In this comment we demonstrate that their results for both parameters are erratic, inaccurate, and unreliable.