Energy levels, oscillator strengths and lifetimes in Si-like Ca VII

Abstract

Energy levels, oscillator strengths and transition probabilities for transitions among the fine-structure levels of the terms belonging to the 3s 2 3p 2 , 3s3p 3 , 3s 2 3p3d, 3p 4 , 3s 2 3p4s, 3s 2 3p4p, 3s 2 3p4d and 3s 2 3p4f configurations of Ca VII are calculated using extensive configuration-interaction (CI) wavefunctions obtained with the CIV3 (configuration interaction version 3) computer code of Hibbert. The relativistic effects in intermediate coupling are incorporated by means of the Breit-Pauli Hamiltonian which consists of the non-relativistic term plus the one-body mass correction, Darwin term, and spin-orbit, spin-other-orbit, and spin-spin operators. Small adjustments to the diagonal elements of the Hamiltonian matrices have been made, so that the energy splittings are as close as possible to the experimental values. The energy splitting of 70 fine-structure levels, oscillator strengths and transition probabilities for electric-dipole-allowed and intercombination transitions and, also the lifetimes of fine-structure levels are presented and compared with available experimental and other theoretical results. Our calculated fine-structure energies, including their ordering, show excellent agreement (better than 0.5%) with the available experimental results. In this calculation, we also predict new data for several levels where no other theoretical and experimental results are available.

Energy levels, oscillator strengths and lifetimes in Ar V

“…Froese-Fischer et al [18] calculated the relativistic energy levels, lifetimes and transition probabilities for the Na-like to Ar-like sequences, using non-orthogonal spline CI, Multi-Configuration Hartree-Fock (MCHF) and also Multi-Configuration Dirac-Hartree-Fock (MCDHF) methods. Recently, we have carried out calculations of excitation energies, oscillator strengths, transition probabilities and lifetimes for electric-dipole-allowed and inter-combination transitions in silicon-like calcium [19], using configuration-interaction code [20] and the Breit-Pauli Hamiltonian [21].…”

Transition spectral parameters of In-like Ba, La, and Ce ions

“…between A l and A v of transition probabilities such as the transitions 5s 2 5p 2 P -4f5s5p 4 D of Ba VIII, La IX and Ce X, that is because the transitions 5s 2 5p 2 P -4f5s5p 4 D of Ba VIII, La IX and Ce X are weak transitions (the oscillator strengths f l are less than 0.1) being sensitive to mixing. So the large differences between A l and A v of transition probabilities might be due to the small oscillator strengths f l sensitive to cancelation effects [18].…”

Fine-structure energy levels, oscillator strengths and lifetimes in Cu XVI

“…Vilkas and Ishikawa [20] carried out relativistic multireference many-body perturbation theory [21] calculations for the term energies of the ground and 26 lowest excited levels arising from the 3s 2 3p 2 , 3s3p 3 and 3s 2 3p3d configurations in silicon-like ions with nuclear charges Z = 24-30. Tayal and Gupta carried out calculations of excitation energies, oscillator strengths, transition probabilities and lifetimes for electric-dipole-allowed and inter-combination transitions in silicon-like Ca VII [22] and Ar V [23], using the CI code [24] and the Breit-Pauli Hamiltonian [25]. The spectrum of the Cu XVI ion has been studied by several workers [26][27][28][29][30][31][32].…”