scholarly journals Transition Parameters for Doubly Ionized Lanthanum

2012 ◽  
Vol 2012 ◽  
pp. 1-15 ◽  
Author(s):  
Betül Karaçoban ◽  
Leyla Özdemir
Keyword(s):  
Least Squares ◽  
Configuration Interaction ◽  
Electric Dipole ◽  
Transition Probabilities ◽  
Energy Levels ◽  
Relativistic Effects ◽  
Oscillator Strengths ◽  
Least Squares Fitting ◽  
Hartree Fock

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.

Calculation of Wavelengths, Transition Probabilities and Oscillator Strengths for E1 and M1 Transitions in Cu-Like Au Ion

2015 ◽  
Vol 723 ◽  
pp. 799-803
Author(s):  
Min Xu
Keyword(s):  
Excited States ◽  
Magnetic Dipole ◽  
Configuration Interaction ◽  
Electric Dipole ◽  
Transition Probabilities ◽  
Energy Levels ◽  
Oscillator Strengths ◽  
Forbidden Transitions ◽  
Calculation Results ◽  
Good Agreement

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.

scholarly journals Extended theoretical transition data in C i–iv

2021 ◽  
Vol 502 (3) ◽  
pp. 3780-3799
Author(s):  
W Li ◽  
A M Amarsi ◽  
A Papoulia ◽  
J Ekman ◽  
P Jönsson
Keyword(s):  
Transition Probabilities ◽  
Energy Levels ◽  
Oscillator Strengths ◽  
Atomic Data ◽  
Internal Validation ◽  
Hartree Fock ◽  
Relativistic Configuration ◽  
The Difference ◽  
The One ◽  
Relative Differences

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.

scholarly journals Chromospheric and Coronal Spectra

1995 ◽  
Vol 10 ◽  
pp. 580-582
Author(s):  
Carole Jordan
Keyword(s):  
Transition Probabilities ◽  
Energy Levels ◽  
Relativistic Effects ◽  
Uv Spectra ◽  
Oscillator Strengths ◽  
Atomic Data ◽  
Recombination Rates ◽  
Electron Collisions ◽  
Close Coupling ◽  
Radiative Processes

The interpretation of chromospheric and coronal spectra requires accurate ionization and recombination rates, collision strengths and transition probabilities. Recent projects to improve calculations of opacities in stellar interiors have led to a large amount of new atomic data. Some current and potential applications of atomic data to chromospheric and coronal spectra are mentioned below.Strong chromospheric lines are optically thick, and the solution of the radiative transfer equations can depend on atomic data for other species contributing to the background opacity. Many lines in the spectra of stars with hot coronae are excited by electron collisions, but in the cooler non-coronal giants radiative processes involving the H Lyman α and β lines become more important (see Jordan 1988a). Photo-ionization rates from ground configuration excited terms and oscillator strengths to high levels are still needed.Fe II is an important ion producing emission lines in stellar chromospheres. Several excitation mechanisms contribute to the observed spectra (Jordan 1988b). Permitted lines to the ground term and low lying metastable terms have high optical depths and transfer photons to spin forbidden lines sharing a common upper level (e.g. mults. uv 1 and uv 3 transfer photons to mults. uv 32 and 61). Line intensity ratios yield the optical depth in the optically thick lines. The strong H Ly α line in cool giants and supergiants excites high levels in Fe II, resulting in strong decays in multiplets such as uv 391 and 399. A large number of f-values are required to interpret the lines formed by these radiative processes. Nahar & Pradhan (1994) have published some results from the Opacity Project, calculated by using the close coupling method and observed energy levels (which introduce some allowance for relativistic effects). In most cases these f-values agree with experimental results and the calculations by Kurucz (1988) to within 10%. The latter are still needed for the interpretation of stellar uv spectra because of the treatment of spin-forbidden lines.

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
Keyword(s):  
Electric Dipole ◽  
Transition Probabilities ◽  
Oscillator Strengths ◽  
Hartree Fock

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.

Multiconfiguration Dirac–Hartree–Fock calculations of energy levels, wavelengths, weighted oscillator strengths, transitions probabilities and lifetimes of Cd XLVII

2021 ◽  
Vol 0 (0) ◽  
Author(s):  
Dhia Elhak Salhi ◽  
Soumaya Manai ◽  
Sirine Ben Nasr ◽  
Haikel Jelassi
Keyword(s):  
Missing Data ◽  
Quantum Electrodynamics ◽  
Transition Probabilities ◽  
Energy Levels ◽  
Oscillator Strengths ◽  
Accurate Data ◽  
Cadmium Ion ◽  
Hartree Fock ◽  
First Time ◽  
Good Agreement

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.

scholarly journals Energies, Landé g-factors, oscillator strengths, and transition probabilities in Cs-like Pr V

2015 ◽  
Vol 93 (12) ◽  
pp. 1439-1445
Author(s):  
Betül Karaçoban Usta ◽  
Sevda Doğan
Keyword(s):  
Electric Dipole ◽  
Transition Probabilities ◽  
Oscillator Strengths ◽  
Hartree Fock ◽  
G Factors

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.

scholarly journals Theoretical investigation of oscillator strengths and lifetimes in Ti II

2020 ◽  
Vol 643 ◽  
pp. A156
Author(s):  
W. Li ◽  
H. Hartman ◽  
K. Wang ◽  
P. Jönsson
Keyword(s):  
Transition Probabilities ◽  
Energy Levels ◽  
Electric Quadrupole ◽  
General Purpose ◽  
Oscillator Strengths ◽  
Atomic Data ◽  
Excitation Energies ◽  
Hartree Fock ◽  
Self Energy ◽  
Theoretical Predictions

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.

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

2021 ◽  
Author(s):  
Miao Wu ◽  
Zhencen He
Keyword(s):  
Quantum Electrodynamics ◽  
Transition Probabilities ◽  
Energy Levels ◽  
Oscillator Strengths ◽  
Spectral Parameters ◽  
Hartree Fock ◽  
Experimental Values ◽  
Theoretical Results ◽  
Good Agreement ◽  
Line Strengths

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.

A study for hydrogen-like lawrencium

2018 ◽  
Vol 96 (12) ◽  
pp. 1359-1364
Author(s):  
Güldem Ürer
Keyword(s):  
Quantum Electrodynamics ◽  
Transition Probabilities ◽  
Energy Levels ◽  
Oscillator Strengths ◽  
Atomic Data ◽  
Hartree Fock ◽  
Atomic Structures ◽  
Transverse Photon ◽  
Qed Effects ◽  
Hydrogenic Ions

Studying hydrogenic ions with high Z is an occasion to understand atomic structure. It also provides a reliable test of methods used to determine atomic structures. Many fields and applications require precise atomic data. For this reason, a hydrogen-like study is performed for lawrencium (Lr102+, Z = 103). The energy levels of hydrogen-like lawrencium are calculated with both multiconfiguration Hartree–Fock (MCHF) and multiconfiguration Dirac–Fock (MCDF) methods. The calculations contain Breit–Pauli relativistic corrections in MCHF calculation and the transverse photon and quantum electrodynamics (QED) effects in MCDF calculation along with electron correlations. In addition, some transition parameters (wavelengths, λ, logarithmic weighted oscillator strengths, log(gf) value, and transition probabilities, Aki) for allowed (E1) and forbidden (E2 and M1) transitions are investigated. The results from this study are compared with only a few theoretical works, but there is no available experimental data yet for Lr102+.

scholarly journals Calculations for energies, lifetimes, and transition parameters of E1 and E2 transitions in Mg II

2019 ◽  
Vol 97 (8) ◽  
pp. 828-841
Author(s):  
Betül Karaçoban Usta
Keyword(s):  
Electric Dipole ◽  
Transition Probabilities ◽  
Electric Quadrupole ◽  
Oscillator Strengths ◽  
Ionized Magnesium ◽  
Hartree Fock ◽  
First Time ◽  
Theoretical Results

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.

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