Complementary investigations using the MCDF and RQDO methods

Abstract

Theoretical oscillator strengths for fine-structure lines of electric dipole (E1) allowed transitions for a number of ions belonging to the Be, As, and Ge sequences, are reported. Both ab initio (multiconfiguration Dirac-Fock) and model potential (relativistic quantum defect orbital) techniques have been used. A comparative analysis of the two sets of f-values, as well as with other data found in the literature, has been carried out. For most of the studied ions and transitions, the results achieved with the two methodologies are, overall, in rather good agreement.

Ab-Initio Calculations of Level Energies, Oscillator Strengths and Radiative Rates for E1 Transitions in Beryllium-Like Iron

“…The self-consistent procedure (RSCF) including EOL type calculations (extended optimal levels) is done layer by layer, at each stage the outer orbitals are optimized. The EOL type calculations construct orbitals from an average energy functional in which the fine-structure levels are given the weight (2J + 1) [30]. This procedure is performed for every J-value separately.…”

“…Jian-Hui et al [28] have calculated energy levels, oscillator strengths, transition probabilities and wavelengths of Fe 22+ using the MCDF method with the inclusion of vacuum polarization and Breit interaction. Charro et al [29,30] have calculated some oscillator strengths of Be-like iron up to n = 2, 3 using the relativistic quantum defect orbital (RQDO) method and the MCDF method, but there were no Breit corrections included in the calculations. By using the FAC code Landi and Gu [31] calculated energy levels, oscillator strengths and transition probabilities for 166 fine-structure levels of Fe 22+ belonging to the complexes 1s 2 2lnl , n = 2 − 5, l = s, p, d, f, g.…”

Stellar laboratories

“…These works were subsequently extended by Aggarwal & Keenan (2015) to transitions involving the 4s 2 4p 5 , 4s 2 4p 4 4ℓ, 4s4p 6 , 4s 2 4p 4 5ℓ, 4s 2 4p 3 4d 2 , 4s4p 5 4ℓ, and 4s4p 5 5ℓ configurations. For Sr vi, relativistic quantum defect orbital (RQDO) and MCDF calculations of oscillator strengths were carried out by Charro & Martín (1998, 2005 for the 4p 3 -4p 2 5s transition array while the same methods were used by Charro & Martín (2002, 2005 for investigating the 4p 2 -4p5s transitions in Sr vii. In the case of Te vi, Chou & Johnson (1997) performed third-order relativistic many-body perturbation theory (MBPT) calculations to evaluate the rates for 5s -5p transitions while Migdalek & Garmulewicz (2000) used a relativistic ab initio model potential approach with explicit local exchange to produce oscillator strengths.…”