“Electron collisional excitation of argon-like Ni XI using the Breit-Pauli R-matrix method”
[Eur. Phys. J. D 42, 235–241 (2007)] Electron impact excitation of Ni XI
Astrophysics Research Centre, School of Mathematics and Physics, Queen's University Belfast, Belfast BT7 1NN, Northern Ireland, UK
Corresponding author: a K.Aggarwal@qub.ac.uk
Published online: 24 October 2007
In a recent paper, Verma et al. [Eur. Phys. J. D 42, 235 (2007)] have reported results for energy levels, radiative rates, collision strengths, and effective collision strengths for transitions among the lowest 17 levels of the (1s22s22p6)3s23p6, 3s23p53d and 3s3p63d configurations of Ni xi. They adopted the civ3 and R-matrix codes for the generation of wavefunctions and the scattering process, respectively. In this paper, through two independent calculations performed with the fully relativistic darc (along with grasp) and fac codes, we demonstrate that their results are unreliable. New data are presented and their accuracy is assessed.
PACS: 34.80.Dp – Atomic excitation and ionization by electron impact
© EDP Sciences, Società Italiana di Fisica, Springer-Verlag, 2007