scholarly journals Lifetimes, oscillator strengths, and transition probabilities for Ce IV

2017 ◽  
Vol 95 (11) ◽  
pp. 1103-1114
Author(s):  
Betül Karaçoban Usta ◽  
Büşra Alparslan

The lifetimes for the levels of 5p6nf (n = 5–30), 5p6np (n = 6–30), 5p6nd (n = 5–30), 5p6ng (n = 5–30), and 5p6ns (n = 7–30) configurations and the transition parameters for the electric dipole transitions between these levels have been calculated using the relativistic Hartree–Fock (HFR) method for triply ionized cerium (Ce IV, Z = 58). We have compared the results with the previously reported available calculations and experiments in the literature. Moreover, some new transition probabilities, oscillator strengths, and lifetime values for highly excited levels in Ce IV, not appearing in databases, have been obtained using this method.

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.


2015 ◽  
Vol 93 (12) ◽  
pp. 1439-1445
Author(s):  
Betül Karaçoban Usta ◽  
Sevda Doğan

We have calculated relativistic energies and Landé g-factors for the levels of 5p6nf (n = 4–30), 5p6np (n = 6–30), 5p6nd (n = 5–30), 5p6ng (n = 5–30) and 5p6ns (n = 6–30) configurations and the transition parameters, such as wavelengths, oscillator strengths, and transition probabilities (or rates), for the electric dipole (E1) transitions between these levels in quadruply ionized praseodymium (Pr V, Z = 59) by using the relativistic Hartree–Fock method. We have compared the results with available calculations and experiments in the literature.


2019 ◽  
Vol 97 (8) ◽  
pp. 828-841
Author(s):  
Betül Karaçoban Usta

The lifetimes for 2p6ns (n = 4–15), 2p6nd (n = 3–15), 2p6ng (n = 5–15), 2p6ni (n = 7–15), 2p6np (n = 3–15), 2p6nf (n = 4–15), 2p6nh (n = 6–15), 2p53s2, 2p53snp (n = 3, 4), 2p53p2, 2p53sns (n = 4, 5), 2p53snd (n = 3, 4), and 2p53s4f configurations and the transition parameters for the electric dipole (E1) and electric quadrupole (E2) transitions between valence excitation levels have been calculated using the relativistic Hartree–Fock method for singly ionized magnesium (Mg II, Z = 12). Comparisons are made with experimental and other available theoretical results to assess the reliability and accuracy of the present calculations. Moreover, some new wavelengths, oscillator strengths, and transition probabilities of E1 and E2 transitions and lifetime values have been obtained using this method. These results are reported for the first time in this work.


2021 ◽  
Vol 502 (3) ◽  
pp. 3780-3799
Author(s):  
W Li ◽  
A M Amarsi ◽  
A Papoulia ◽  
J Ekman ◽  
P Jönsson

ABSTRACT Accurate atomic data are essential for opacity calculations and for abundance analyses of the Sun and other stars. The aim of this work is to provide accurate and extensive results of energy levels and transition data for C i–iv. The Multiconfiguration Dirac–Hartree–Fock and relativistic configuration interaction methods were used in this work. To improve the quality of the wavefunctions and reduce the relative differences between length and velocity forms for transition data involving high Rydberg states, alternative computational strategies were employed by imposing restrictions on the electron substitutions when constructing the orbital basis for each atom and ion. Transition data, for example, weighted oscillator strengths and transition probabilities, are given for radiative electric dipole (E1) transitions involving levels up to 1s22s22p6s for C i, up to 1s22s27f for C ii, up to 1s22s7f for C iii, and up to 1s28g for C iv. Using the difference between the transition rates in length and velocity gauges as an internal validation, the average uncertainties of all presented E1 transitions are estimated to be 8.05 per cent, 7.20 per cent, 1.77 per cent, and 0.28 per cent, respectively, for C i–iv. Extensive comparisons with available experimental and theoretical results are performed and good agreement is observed for most of the transitions. In addition, the C i data were employed in a re-analysis of the solar carbon abundance. The new transition data give a line-by-line dispersion similar to the one obtained when using transition data that are typically used in stellar spectroscopic applications today.


1979 ◽  
Vol 57 (2) ◽  
pp. 147-151 ◽  
Author(s):  
J. Migdałek

The relativistic oscillator strengths for the np2 → np(n + 1)s transition array as well as the lifetimes of levels of the np(n + 1)s configuration in SnI and PbI spectra were calculated in jj and intermediate coupling. The relativistic radial integrals were computed employing the wave functions obtained by a semiempirical approach which allowed for exchange effects. The results obtained are compared with existing experimental and theoretical data. The significance of intermediate coupling for oscillator strengths computations is discussed. The agreement with experiment is for the present semiempirical results generally better (particularly for the PbI spectrum) than for oscillator strength deduced from 'Optimized Hartree–Fock–Slater' transition probabilities, which were published previously.


2021 ◽  
Vol 0 (0) ◽  
Author(s):  
Dhia Elhak Salhi ◽  
Soumaya Manai ◽  
Sirine Ben Nasr ◽  
Haikel Jelassi

Abstract Energy levels, wavelengths, weighted oscillator strengths, transition probabilities and lifetimes are calculated for all levels of 1s 2 and 1snl (n = 2–6) configurations of He-like cadmium ion (Cd XLVII). The calculations were carried out using three codes GRASP2018, FAC and AMBiT in order to provide theoretically the most accurate data. Transition probabilities are reported for all the E1, E2, M1 and M2 transitions. Breit interactions and quantum electrodynamics effects are included in the RCI calculations. Comparisons were made with other calculations and a good agreement was found which confirms the reliability of our results. We present some missing data for the He-like cadmium in this paper for the first time.


2015 ◽  
Vol 723 ◽  
pp. 799-803
Author(s):  
Min Xu

Wavelengths, transition probabilities and oscillator strengths have been calculated for electric dipole (E1) transitions and magnetic dipole (M1) transitions in Cu-like Au ion. These values are obtained in the configuration interaction (CI) and using the fully relativistic multiconfiguration Dirac-Fock (MCDF) method including quantum electrodynamical (QED) effect and Breit correction. Obtained energy levels of some excited states in Cu-like Au ion from the method are generally in good agreement with valuable theoretical and experimental results. The calculation results indicate that for high-Z highly ionized atom, some forbidden transitions are very important.


2020 ◽  
Vol 643 ◽  
pp. A156
Author(s):  
W. Li ◽  
H. Hartman ◽  
K. Wang ◽  
P. Jönsson

Aims. Accurate atomic data for Ti II are essential for abundance analyses in astronomical objects. The aim of this work is to provide accurate and extensive results of oscillator strengths and lifetimes for Ti II. Methods. The multiconfiguration Dirac–Hartree–Fock and relativistic configuration interaction (RCI) methods, which are implemented in the general-purpose relativistic atomic structure package GRASP2018, were used in the present work. In the final RCI calculations, the transverse-photon (Breit) interaction, the vacuum polarisation, and the self-energy corrections were included. Results. Energy levels and transition data were calculated for the 99 lowest states in Ti II. Calculated excitation energies are found to be in good agreement with experimental data from the Atomic Spectra Database of the National Institute of Standards and Technology based on the study by Huldt et al. Lifetimes and transition data, for example, line strengths, weighted oscillator strengths, and transition probabilities for radiative electric dipole (E1), magnetic dipole (M1), and electric quadrupole (E2) transitions, are given and extensively compared with the results from previous calculations and measurements, when available. The present theoretical results of the oscillator strengths are, overall, in better agreement with values from the experiments than the other theoretical predictions. The computed lifetimes of the odd states are in excellent agreement with the measured lifetimes. Finally, we suggest a relabelling of the 3d2(12D)4p y2 D3/2o and z2 P3/2o levels.


Author(s):  
Miao Wu ◽  
Zhencen He

The spectral parameters (energy levels, wavelengths, transition probabilities, line strengths and oscillator strengths) of resonance lines for Ba VIII, La IX and Ce X have been performed using the multiconfiguration Dirac-Hartree-Fock method, the contributions of quantum electrodynamics and Breit interactions correction are taken into considered. The calculated results of energy levels and wavelengths are in good agreement with experimental values and other calculation. The number of energy levels and wavelengths considered is larger than that of any other experiment values and other calculations. The transition probabilities, line strengths and oscillator strengths are also calculated where no other theoretical results and experimental values are available.


2018 ◽  
Vol 96 (10) ◽  
pp. 1098-1103
Author(s):  
Gülay Günday Konan ◽  
Leyla Özdemir

We have reported atomic data including energies and electric dipole (E1) transition parameters, such as wavelengths, transition probabilities (or rates), and weighted oscillator strengths, for Na-like and Mg-like mercury (Hg69+ and Hg68+) using the AUTOSTRUCTURE atomic code, which includes Breit and quantum electrodynamics effects as well as correlation developed by Badnell. We have compared our results with the available theoretical results in the literature. Also, we have presented new results where no other theoretical and experimental results are available.


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