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.

Energies, wavelengths, lifetimes, E1, M1, E2, and M2 transitions rates for the sulfur isoelectronic sequence Fe XI, Nb XXVI–In XXXIV

2017 ◽  
Vol 95 (4) ◽  
pp. 393-401 ◽  
Author(s):  
K. Wang ◽  
S. Li ◽  
R. Si ◽  
C.Y. Chen ◽  
J. Yan ◽  
...  
Keyword(s):  
Quantum Electrodynamics ◽  
Energy Levels ◽  
Theoretical Data ◽  
Electric Quadrupole ◽  
Oscillator Strengths ◽  
Transition Rates ◽  
Isoelectronic Sequence ◽  
Fusion Plasma ◽  
Magnetic Quadrupole ◽  
Theoretical Results

Energies, wavelengths, lifetimes, oscillator strengths, electric dipole (E1), electric quadrupole (E2), magnetic dipole (M1), and magnetic quadrupole (M2) transition rates among the 42 fine structure levels belonging to the 3s23p4, 3s23p33d, and 3s3p5 configurations for S-like Fe and S-like ions with 41 ≤ Z ≤ 49 are calculated using the fully relativistic multiconfiguration Dirac–Fock (MCDF) method. In the calculations, contributions from correlations within the n = 6 complex, Breit interaction, and quantum electrodynamics effects are included. Detailed comparisons are made between the present results and the available experimental and other theoretical data. We found that our calculated energy levels generally agree within ≤0.5% with the experimentally compiled results, and the transition rates agree within ≤12% with other theoretical results for a majority of the transitions. These accurate theoretical data should be beneficial in fusion plasma research and astrophysical applications.

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.

Allowed and forbidden transition rates and corresponding wavelengths for Si-like Au ion (Au65+) by relativistic configuration interaction method

2018 ◽  
Vol 96 (10) ◽  
pp. 1116-1137
Author(s):  
S.M. Hamasha ◽  
A. Almashaqba
Keyword(s):  
Configuration Interaction ◽  
Energy Levels ◽  
Theoretical Data ◽  
Oscillator Strengths ◽  
Atomic Data ◽  
Transition Rates ◽  
Interaction Method ◽  
Configuration Interaction Method ◽  
Relativistic Configuration ◽  
Relativistic Configuration Interaction

Large-scale atomic calculations are carried out to produce data of atomic structure and transitions rates for Si-like Au ion (Au65+). Generated atomic data are essential for modeling of M-shell spectra of gold ions in Au plasma, and fusion research. Energy levels are calculated by applying two methods: the relativistic configuration interaction method (RCI) of the flexible atomic code (FAC) and the multi-reference many body perturbation theory method (MR-MBPT). Energy levels, oscillator strengths, and transition rates are calculated for transitions between excited and ground states from n = 3l to n′l′, where n′ = 4, 5, 6, and 7; and l and l′ are the proper angular momenta of shells n and n′, respectively. The electric dipole (E1), electric quadrupole (E2), electric octupole (E3), magnetic dipole (M1), magnetic quadrupole (M2), and magnetic octupole (M3) transitions are all considered in the calculations. Correlation effects, relativistic effects, and QED effects are also included in the calculations. The two methods yield comparable values of energy levels. Data of energy levels of low-lying states and data for inner shell transitions reported in this study demonstrate good agreement with published experimental and theoretical data.

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.

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.

scholarly journals Theoretical investigation of energy levels and transition data for S II, Cl III, Ar IV

2019 ◽  
Vol 623 ◽  
pp. A155 ◽  
Author(s):  
P. Rynkun ◽  
G. Gaigalas ◽  
P. Jönsson
Keyword(s):  
Energy Levels ◽  
Electric Quadrupole ◽  
General Purpose ◽  
Energy Spectra ◽  
Astrophysical Plasmas ◽  
Internal Validation ◽  
Hartree Fock ◽  
Self Energy ◽  
Relativistic Configuration ◽  
Relativistic Configuration Interaction

Aims. The aim of this work is to present accurate and extensive results of energy spectra and transition data for the S II, Cl III, and Ar IV ions. These data are useful for understanding and probing physical processes and conditions in various types of astrophysical plasmas.Methods. The multiconfiguration Dirac–Hartree–Fock (MCDHF) and relativistic configuration interaction (RCI) methods, which are implemented in the general-purpose relativistic atomic structure package GRASP2K, are used in the present work. In the RCI calculations the transverse-photon (Breit) interaction, the vacuum polarization, and the self-energy corrections are included.Results. Energy spectra are presented comprising the 134, 87, and 103 lowest states in S II, Cl III, and Ar IV, respectively. Energy levels are in very good agreement with NIST database recommended values and associated with smaller uncertainties than energies from other theoretical computations. Electric dipole (E1), magnetic dipole (M1), and electric quadrupole (E2) transition data are computed between the above states together with the corresponding lifetimes. Based on internal validation, transition rates for the majority of the stronger transitions are estimated to have uncertainties of less than 3%.

scholarly journals The Computation of Energy Levels and Oscillator Strengths of Fe X to Fe XIII Involving the Adjustment of Parameters to Achieve Consistency with Observations

1977 ◽  
Vol 43 ◽  
pp. 41-41a
Author(s):  
B.C. Fawcett ◽  
G.E. Bromage ◽  
R.D. Cowan
Keyword(s):  
Ab Initio ◽  
Configuration Interaction ◽  
Energy Levels ◽  
Average Energy ◽  
Oscillator Strengths ◽  
Spin Orbit ◽  
Adjustment Of Parameters

Energy levels and oscillator strengths are calculated for the 3s23pn–3s23pn–13d transition arrays of Fe X, Fe XI, Fe XII and Fe XIII. The Slater radial integrals for these computations are adjusted so as to become consistent with established energy levels. Pertinent configuration interactions are included and the interaction integrals are reduced by up to 35% from values calculated ab initio, to achieve consistency.Initial theroretical calculations are made using the ab initio Hartree-X, Slater-Condon programme of Cowan (1967, 1968), the second of which now includes configuration interaction. The first programme computes values for the average energy of the configuration Eav, the electrostatic direct integrals Fk and exchange integrals Gk , the spin-orbit parameters ζ, and the configuration interaction integrals Rk. From these the second programme computes energy levels, wavelengths and oscillator strengths for the transition arrays concerned.

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.

Excited electronic states of 1, 3-butadiene

1955 ◽  
Vol 230 (1182) ◽  
pp. 322-330 ◽  
Keyword(s):  
Excited States ◽  
Configuration Interaction ◽  
Energy Levels ◽  
Electronic States ◽  
Interaction Method ◽  
Excited Electronic States ◽  
Configuration Interaction Method ◽  
Self Consistent ◽  
Electronic Wave Function ◽  
Orthogonal Set

Approximate self-consistent orbitals for excited electronic states of cis - and trans -1, 3- butadiene are obtained by a modification of Roothaan’s procedure, in the non-empirical π-electron approximation. The integrals used were evaluated by Parr & Mulliken for calculation of the ground-state electronic wave function. The effects of configuration interaction are calculated by an approximate method and compared with an exact calculation. Molecular orbitals have been obtained both with and without the auxiliary condition that spatial factors of both α and β spin-orbitals should be members of a single orthogonal set. Semiempirical values for the basic integrals, due to Pariser & Parr, have also been used to calculate the energies of excited states by the approximate configuration interaction method. Energy levels derived from the Pariser-Parr integrals are in close agreement with observed levels, which differ considerably from those calculated from the Parr-Mulliken non-empirical integrals.

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