scholarly journals Electric dipole transitions between low-lying levels in doubly ionized krypton, xenon, and radon

2018 ◽  
Vol 96 (6) ◽  
pp. 664-671 ◽  
Author(s):  
Selda Eser ◽  
Leyla Özdemir

Using the general-purpose relativistic atomic structure package (GRASP) based on a fully relativistic multiconfiguration Dirac–Fock (MCDF) method, the transition parameters, such as transition rates (probabilities), oscillator strengths, and line strengths for the electric dipole transitions between low-lying levels are evaluated for doubly ionized krypton, xenon, and radon. Breit interactions for relativistic effects and quantum electrodynamical (QED) contributions besides valence and valence–core correlation effects are taken into account in calculations. We compare the results obtained with the available data in the literature and discuss them, when possible.

2016 ◽  
Vol 94 (11) ◽  
pp. 1167-1174 ◽  
Author(s):  
Gülay Günday Konan ◽  
Leyla Özdemir

We have reported energies and electric dipole transition parameters, such as transition probabilities, oscillator strengths, line strengths, and wavelengths for Na-like gold (Au68+, Z = 79) using AUTOSTRUCTURE atomic code. Calculations include Breit and QED contributions besides correlation effects. A few of the results have been compared with available theoretical and experimental results in the literature. Our atomic structure data for sodium-like gold are in good agreement with others. Also we have presented new results for electric dipole transitions in sodium-like gold.


2012 ◽  
Vol 67 (1-2) ◽  
pp. 89-98 ◽  
Author(s):  
Güldem Ürer ◽  
Leyla Özdemir

We have reported a relativistic multiconfiguration Dirac-Fock (MCDF) study on low-lying level structures of protactinium IV (Z =91) and uranium V (Z =92) ions. Excitation energies and electric dipole (E1) transition parameters (wavelengths, oscillator strengths, and transition rates) for these low-lying levels have been given. We have also investigated the influence of the transverse Breit and quantum electrodynamic (QED) contributions besides correlation effects on the level structure. A comparison has been made with a few available data for these ions in the literature.


Galaxies ◽  
2018 ◽  
Vol 6 (3) ◽  
pp. 77 ◽  
Author(s):  
Alan Hibbert

There is an on-going need for accurate oscillator strengths to be used in astrophysical applications, particularly in plasma diagnostics and in the modelling of stellar atmospheres and the interstellar medium. There are several databases in regular use which contain some of the required data, although often insufficiently complete, and sometimes not sufficiently accurate. In addition, several atomic structure packages are available through the literature, or from their individual authors, which would allow further calculations to be undertaken. Laboratory measurements provide an important check on the accuracy of calculated data, and the combined efforts of theorists and experimentalists have succeeded in providing data of an accuracy sufficient for some astrophysical applications. However, the insufficiency or inadequacy of atomic data is a continuing problem. We discuss in the context of appropriate examples some of the principal steps which researchers have taken to calculate accurate oscillator strengths, including both ab initio results and also various extrapolation processes which attempt to improve such results. We also present some examples of the main causes of difficulty in such calculations, particularly for complex (many-electron) ions, and indicate ways in which the difficulties might be overcome.


2012 ◽  
Vol 2012 ◽  
pp. 1-15 ◽  
Author(s):  
Betül Karaçoban ◽  
Leyla Özdemir

The transition parameters such as the wavelengths, weighted oscillator strengths, and transition probabilities (or rates) for the nd (n=5−9)−nf (n=4−8), nd (n=5−9)−np (n=6−9), np (n=6−9)−ns (n=6−10), and ng (n=5−8)−nf (n=4−8) electric dipole (E1) transitions of doubly ionized lanthanum (La III, Z=57) have been calculated using the relativistic Hartree-Fock (HFR) method. In this method, configuration interaction and relativistic effects have been included in the computations combined with a least squares fitting of the Hamiltonian eigenvalues to the observed energy levels. We have compared the results obtained from this work with the previously available calculations and experiments in literature. We have also reported new transitions with the weighted transition probabilities greater than or equal to 105.


2019 ◽  
Vol 97 (5) ◽  
pp. 529-536
Author(s):  
Selda Eser ◽  
Leyla Özdemir

We have reported the wavelengths, transition probabilities (or rates), oscillator strengths, and line strengths for forbidden transitions (electric quadrupole, E2, and magnetic dipole, M1) in doubly and triply ionized krypton, xenon, and radon using the general-purpose relativistic atomic structure package (GRASP). The results obtained from transitions between the levels of ground state configuration are in agreement with other available results in the literature. The data on forbidden transitions between high levels for these ions have been firstly presented in this work.


2014 ◽  
Vol 92 (6) ◽  
pp. 545-550 ◽  
Author(s):  
Kanti M. Aggarwal ◽  
Francis P. Keenan

We report calculations of energy levels and oscillator strengths for transitions in W XL, undertaken with the general-purpose relativistic atomic structure package (GRASP) and flexible atomic code (FAC). Comparisons are made with existing results and the accuracy of the data is assessed. Discrepancies with the most recent results of S. Aggarwal et al. (Can. J. Phys. 91, 394 (2013)) are up to 0.4 Ryd and up to two orders of magnitude for energy levels and oscillator strengths, respectively. Discrepancies for lifetimes are even larger, up to four orders of magnitude for some levels. Our energy levels are estimated to be accurate to better than 0.5% (i.e., 0.2 Ryd), whereas results for oscillator strengths and lifetimes should be accurate to better than 20%.


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