Related papers: Validity of the ICFT R-matrix method: Be-like Al$^…
There are major discrepancies between recent ICFT (Intermediate Coupling Frame Transformation) and DARC (Dirac Atomic R-matrix Code) calculations (Fern\'andez-Menchero et al. 2014, Astron. Astroph. 566 A104, Aggarwal et al. 2016 Mon. Not. R…
We have carried-out two intermediate coupling frame transformation (ICFT) R-matrix calculations for the electron-impact excitation of C-like Fe $^{20+}$, both of which use the same expansions for their configuration interaction (CI) and…
There have been discussions in the recent literature regarding the accuracy of the available electron impact excitation rates (equivalently effective collision strengths $\Upsilon$) for transitions in Be-like ions. In the present paper we…
Modeling the spectral emission of low-charge iron group ions enables the diagnostic determination of the local physical conditions of many cool plasma environments such as those found in H II regions, planetary nebulae, active galactic…
Aims. This work reports radiative transition rates and electron impact excitation collision strengths for levels of the 3s23p, 3s3p2, 3s24s, and 3s23d configurations of Siii. Methods. The radiative data were computed using the…
Emission lines of Be-like ions are frequently observed in astrophysical plasmas, and many are useful for density and temperature diagnostics. However, accurate atomic data for energy levels, radiative rates (A-values) and effective electron…
Emission and absorption features from C-like ions serve as temperature and density diagnostics of astrophysical plasmas. $R$-matrix electron-impact excitation data sets for C-like ions in the literature merely cover a few ions, and often…
Results for energy levels, radiative rates and electron impact excitation (effective) collision strengths for transitions in Be-like Cl XIV, K XVI and Ge XXIX are reported. For the calculations of energy levels and radiative rates the…
This work reports radiative transition rates and electron impact excitation rate coefficients for levels of the n= 3, 4, 5, 6, 7, 8 configurations of Ca II. The radiative data were computed using the Thomas-Fermi-Dirac central potential…
We present results for the electron-impact excitation of highly-charged sulphur ions (S8+ - S11+) obtained using the intermediate-coupling frame transformation R-matrix approach. A detailed comparison of the target structure has been made…
We report calculations of energy levels, radiative rates and electron impact excitation cross sections and rates for transitions in Be-like Ti XIX. The GRASP (General-purpose Relativistic Atomic Structure Package) is adopted for calculating…
Astrophysical plasma codes are built on atomic databases. In the current atomic databases, R-matrix electron-impact excitation data of O-like ions are limited. The accuracy of plasma diagnostics with O-like ions depends on the availability…
The five J$\Pi$ levels within a $np^2$ or $np^4$ ground state complex provide an excellent testing ground for the comparison of theoretical line ratios with astrophysically observed values, in addition to providing valuable electron…
In a recent paper, Mohan et al. [Can. J. Phys. {\bf 95} (2017) 173] have reported results for collision strengths ($\Omega$) and effective collision strengths ($\Upsilon$) for transitions from the ground to higher 51 excited levels of…
There are major discrepancies between recent B-spline R-matrix (BSR) and Dirac Atomic R-matrix Code (DARC) calculations regarding electron-impact excitation rates for transitions in Mg$^{4+}$, with claims that the DARC calculations are much…
Effective collision strengths for forbidden transitions among the 5 energetically lowest finestructure levels of O II are calculated in the Breit-Pauli approximation using the R-matrix method. Results are presented for the electron…
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…
Spectral lines from N-like ions can be used to measure the temperature and density of various types of astrophysical plasmas. The atomic databases of astrophysical plasma modelling codes still have room for improvement in their…
We present results for the inner-shell electron-impact excitation of Fe$^{15+}$ using the intermediate-coupling frame transformation {\it R}-matrix approach in which Auger-plus-radiation damping has been included. The target and…
Collision strengths for electron-impact of fine-structure level excitation within the ground term of Ne$^{+}$ and Ne$^{2+}$ are calculated using the Breit-Pauli, Intermediate Coupling Frame Transformation, and DARC $R$-matrix methods.…