scholarly journals Comment on “Multiconfiguration Dirac–Fock energy levels and radiative rates for Br-like tungsten” by S. Aggarwal, A.K.S. Jha, and M. Mohan [Can. J. Phys. 91, 394 (2013)]

2014 ◽  
Vol 92 (6) ◽  
pp. 545-550 ◽  
Author(s):  
Kanti M. Aggarwal ◽  
Francis P. Keenan
Keyword(s):  
Atomic Structure ◽  
Energy Levels ◽  
General Purpose ◽  
Oscillator Strengths ◽  
Better Than

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%.

scholarly journals Radiative rates for E1, E2, M1, and M2 transitions among the 3s23p5, 3s3p6, and 3s23p43d configurations of Cl-like W LVIII

2014 ◽  
Vol 92 (10) ◽  
pp. 1166-1177 ◽  
Author(s):  
Kanti M. Aggarwal ◽  
Francis P. Keenan
Keyword(s):  
Atomic Structure ◽  
Radiative Decay ◽  
Energy Levels ◽  
General Purpose ◽  
Decay Rates ◽  
Better Than

We report calculations of energy levels, radiative decay rates, and lifetimes for transitions among the 3s23p5, 3s3p6, and 3s23p43d configurations of Cl-like W LVIII. The general-purpose relativistic atomic structure package (GRASP) has been adopted for our calculations. Comparisons are made with the most recent results of Mohan et al. (Can. J. Phys. 92, 177 (2014). doi:10.1139/cjp-2013-0348) and discrepancies in lifetimes are noted, up to four orders of magnitude in some instances. Our energy levels are estimated to be accurate to better than 0.5%, whereas results for radiative rates and lifetimes should be accurate to better than 20%.

Fully relativistic atomic structure calculations for W XLIV for determination of plasma diagnostic terms

2017 ◽  
Vol 95 (10) ◽  
pp. 950-957
Author(s):  
Arun Goyal ◽  
Rinku Sharma ◽  
A.K. Singh ◽  
Man Mohan
Keyword(s):  
Atomic Structure ◽  
Quantum Electrodynamics ◽  
Energy Levels ◽  
General Purpose ◽  
Oscillator Strengths ◽  
Plasma Diagnostic ◽  
Fusion Plasma ◽  
Atomic Structure Calculations ◽  
Structure Calculations

We report accurate calculations of W XLIV through application of multi-configuration Dirac–Fock wave functions. We have calculated the energies for the lowest 100 fine structure levels, transition wavelengths, radiative rates, oscillator strengths, and line strengths for electric (E1) and magnetic dipole (M1) transitions with the extended average level multi-configurational Dirac–Fock method in the General-Purpose Relativistic Atomic Structure Package (GRASP). We have taken into account the electron correlations, quantum electrodynamics (QED) and Breit corrections in our calculations. We have also performed parallel calculations with the flexible atomic code (FAC) to assess the accuracy of our calculations. This is a fully relativistic code that provides a variety of atomic parameters, and (generally) yields results for energy levels and radiative rates comparable to GRASP. Our calculated results match well with experimentally observed results that are obtained in ASDEX upgrade Tokamak. Additionally, we have also provided the line intensity ratios and electron density for W XLIV, which is useful and important in plasma diagnostics and modeling in future International Thermonuclear Experimental Reactor (ITER) experiments. We believe that our results would be beneficial in the areas of fusion plasma research and astrophysical investigations and applications.

Accurate study on the properties of spectral lines for Na-like Cr13+

2019 ◽  
Vol 97 (4) ◽  
pp. 436-442
Author(s):  
A.K. Singh ◽  
Mayank Dimri ◽  
Dishu Dawra ◽  
Alok K.S. Jha ◽  
Man Mohan
Keyword(s):  
Configuration Interaction ◽  
Energy Levels ◽  
Electric Quadrupole ◽  
General Purpose ◽  
Spectral Lines ◽  
Oscillator Strengths ◽  
Fusion Plasma ◽  
Configuration Interaction Method ◽  
Magnetic Quadrupole ◽  
Configuration Interaction Calculations

An extended calculation of energy levels, radiative rates, and lifetimes are reported for sodium-like chromium. Extensive configuration interaction calculations have been performed using general-purpose relativistic atomic structure package (GRASP). The radiative rates, oscillator strengths, and line strengths are listed for all electric dipole (E1) transitions. However, for magnetic dipole (M1), electric quadrupole (E2), and magnetic quadrupole (M2) transitions, only radiative rates are listed. The importance of valence–valence (VV) and core–valence (CV) correlation effects in the calculation of energy levels have also been shown. To confirm the accuracy of the present results for energy levels by GRASP, independent calculations have been performed by using Flexible Atomic Code (FAC) and configuration interaction method (CIV3). The accuracy of the present levels, wavelengths, transition rates, and lifetimes are assessed by comparing them to available experimental and other theoretical results. We believe that our extensive results may be beneficial in fusion plasma research and astrophysical investigations and applications.

scholarly journals Electric quadrupole (E2) and magnetic dipole (M1) transitions for doubly and triply ionized krypton, xenon, and radon

2019 ◽  
Vol 97 (5) ◽  
pp. 529-536
Author(s):  
Selda Eser ◽  
Leyla Özdemir
Keyword(s):  
Magnetic Dipole ◽  
Atomic Structure ◽  
Ground State ◽  
Transition Probabilities ◽  
Electric Quadrupole ◽  
General Purpose ◽  
Oscillator Strengths ◽  
Ground State Configuration ◽  
Forbidden Transitions ◽  
State Configuration

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.

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 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
Keyword(s):  
Atomic Structure ◽  
Electric Dipole ◽  
Relativistic Effects ◽  
General Purpose ◽  
Oscillator Strengths ◽  
Transition Rates ◽  
Correlation Effects ◽  
Core Correlation ◽  
Line Strengths

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.

scholarly journals Atomic Structure Calculations for Neutral Oxygen

2016 ◽  
Vol 2016 ◽  
pp. 1-7 ◽  
Author(s):  
Norah Alonizan ◽  
Rabia Qindeel ◽  
Nabil Ben Nessib
Keyword(s):  
Atomic Structure ◽  
Energy Levels ◽  
Oscillator Strengths ◽  
Nist Database ◽  
Experimental Values ◽  
Atomic Structure Calculations ◽  
Structure Calculations

Energy levels and oscillator strengths for neutral oxygen have been calculated using the Cowan (CW), SUPERSTRUCTURE (SS), and AUTOSTRUCTURE (AS) atomic structure codes. The results obtained with these atomic codes have been compared with MCHF calculations and experimental values from the National Institute of Standards and Technology (NIST) database.

scholarly journals Atomic data for Ne-like ions useful in plasma diagnostic

2018 ◽  
Vol 96 (1) ◽  
pp. 36-54 ◽  
Author(s):  
Narendra Singh ◽  
Sunny Aggarwal ◽  
Man Mohan
Keyword(s):  
Transition Probability ◽  
Energy Levels ◽  
General Purpose ◽  
Oscillator Strengths ◽  
Atomic Data ◽  
Recent Measurement ◽  
Plasma Diagnostic ◽  
Transition Energies ◽  
New Energy ◽  
Qed Effects

Motived by the recent measurement of transition lines for Ne-like Hf and W, we have reported atomic data in the form of multiconfiguration Dirac–Fock transition energies and wavefunction compositions of 209 levels belonging to the configurations 2s22p6, 2s22p5ns (n = 3, 4, 5, 6, 7), 2s22p5np (n = 3, 4, 5, 6, 7), 2s22p5nd (n = 3, 4, 5, 6, 7), 2s22p5nf (n = 4, 5), 2s22p55g, 2s2p6ns (n = 3, 4, 5), 2s2p6np (n = 3, 4, 5), 2s2p6nd (n = 3, 4, 5), 2s2p6nf (n = 4, 5), and 2s2p65g of Hf LXIII, Ta LXIV, W LXV, and Re LXVI. Radiative rates, oscillator strengths, transition wavelengths, and line strengths have been calculated for ground state electric dipole (E1) transition among these levels. These values were obtained using GRASP (general-purpose relativistic atomic structure package) code, which includes Breit and QED effects along with Dirac–Fock potential and second-order Coulomb interaction. We have compared our results with the data compiled using FAC (flexible atomic code) and also with the recent results available in the literature. The accuracy of the data is assessed. We predict new energy levels, oscillator strength, and transition probability data, where no other theoretical or experimental results are available, which will form the basis for future experimental work.

Ab Initio Determination of Atomic Structure and Stark Broadening Parameters: Pb IV and Recent Results

2011 ◽  
Vol 20 (4) ◽  
Author(s):  
R. Hamdi ◽  
N. Ben Nessib ◽  
M. S. Dimitrijević ◽  
S. Sahal-Bréchot
Keyword(s):  
Ab Initio ◽  
Atomic Structure ◽  
Energy Levels ◽  
Relativistic Effects ◽  
Spectral Lines ◽  
Oscillator Strengths ◽  
Perturbation Approach ◽  
Stark Broadening ◽  
Relativistic Approach

AbstractWe present a review of our previous ab initio calculations of Stark broadening parameters using semi-classical perturbation method for the calculation of Stark widths and shifts, and the SUPERSTRUCURE (SST) code for the determination of atomic structure. SST code takes into account the configuration interactions and relativistic effects. New results are also presented for some spectral lines of Pb IV. Energy levels and oscillator strengths are calculated using Hartree-Fock relativistic approach, and the Stark broadening parameters are determined using a semiclassical perturbation approach.

scholarly journals Theoretical studies of energy levels and transition data for Zr III

2020 ◽  
Vol 637 ◽  
pp. A10 ◽  
Author(s):  
P. Rynkun ◽  
G. Gaigalas ◽  
P. Jönsson
Keyword(s):  
Energy Levels ◽  
Electric Quadrupole ◽  
General Purpose ◽  
Oscillator Strengths ◽  
Energy Spectra ◽  
Transition Rates ◽  
Hartree Fock ◽  
Self Energy ◽  
Relativistic Configuration ◽  
Experimental Values

Aims. We seek to present accurate and extensive transition data for the Zr III ion. These data are useful in many astrophysical applications. Methods. We used the multiconfiguration Dirac-Hartree-Fock and relativistic configuration interaction (RCI) methods, which are implemented in the general-purpose relativistic atomic structure package GRASP2018. The transverse-photon (Breit) interaction, vacuum polarization, and self-energy corrections are included in the RCI computations. Results. Energy spectra were calculated for the 88 lowest states in the Zr III ion. The root-mean-square deviation obtained in this study for computed energy spectra from the experimental data is 450 cm−1. Electric dipole (E1), magnetic dipole (M1), and electric quadrupole (E2) transition data, line strengths, weighted oscillator strengths, and transition rates are computed between the above states together with the corresponding lifetimes. The computed transition rates are smaller than the experimental rates and the disagreement for weaker transitions is much larger than the experimental error bars. The computed lifetimes agree with available experimental values within the experimental uncertainties.

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