Comment on "Atomic structure and electron impact excitation of Al-like ions (Ga--Br)" by HB Wang and G Jiang in At. Data Nucl. Data Tables 148 (2022) 101532

In a recent paper, Wang and Jiang (At. Data Nucl. Data Tables 148 (2022) 101532) have reported data for energy levels, radiative rates (A-values), and effective collision strengths ($\Upsilon$) for some transitions of five Al-like ions, namely Ga~XIX, Ge~XX, As~XXI, Se~XXII, and Br~XXIII. On a closer examination we find that their reported data for energy levels and A-values are generally correct, but not for $\Upsilon$. Their $\Upsilon$ values, for all transitions (allowed or forbidden) and for all ions, invariably decrease at higher temperatures. This is mainly because they have adopted a limited range of electron energies for the calculations of collision strengths. We demonstrate this with our calculations with the Flexible Atomic Code (FAC), and conclude that their $\Upsilon$ values are inaccurate, unreliable, and should not be adopted in any applications or modelling analysis.

K.M. Aggarwal, K. W. Smith · 2023