Breit–Pauli atomic structure calculations for sulphur-like titanium

2012 ◽  
Vol 90 (9) ◽  
pp. 833-847 ◽  
Author(s):  
Jagjit Singh ◽  
Sunny Aggarwal ◽  
A.K. Singh ◽  
Man Mohan
Keyword(s):  
Fine Structure ◽  
Oscillator Strength ◽  
Transition Probabilities ◽  
Transition Probability ◽  
Calculated Data ◽  
Oscillator Strengths ◽  
Fine Tuning ◽  
Strong Mixing ◽  
Correct Identification ◽  
Excitation Energies

Configuration interaction calculation has been performed for excitation energies, oscillator strengths, and transition probabilities of 114 fine-structure levels of sulphur-like titanium. The relativistic effects are included in Breit–Pauli approximation by adding mass-correction, Darwin, and spin–orbit interaction terms to the nonrelativistic Hamiltonian. We have adjusted the diagonal elements of Hamiltonian matrices (fine-tuning) before the calculation of oscillator strength and transition probabilities for the electric dipole allowed transitions. Our calculated data are in close agreement with data listed in National Institute of Standards and Technology and other available results. Correct identification of some of the levels become very difficult because of strong mixing among several fine-structure levels. 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.

Large-scale CIV3 calculations of fine-structure energy levels and radiative rates in Al-like copper

2009 ◽  
Vol 87 (8) ◽  
pp. 895-907 ◽  
Author(s):  
G. P. Gupta ◽  
A. Z. Msezane
Keyword(s):  
Fine Structure ◽  
Configuration Interaction ◽  
Large Scale ◽  
Radiative Decay ◽  
Energy Levels ◽  
Decay Rates ◽  
Experimental Results ◽  
Oscillator Strengths ◽  
Correct Identification ◽  
Excitation Energies

We have performed large-scale CIV3 calculations of excitation energies from the ground state for 97 fine-structure levels as well as of oscillator strengths and radiative decay rates for all electric-dipole-allowed and intercombination transitions among the fine-structure levels of the terms belonging to the (1s22s22p6)3s23p, 3s3p2, 3s23d, 3p3, 3s3p3d, 3p23d, 3s3d2, 3s24s, 3s24p, 3s24d, 3s24f, and 3s3p4s configurations of Cu XVII. These states are represented by very extensive configuration-interaction (CI) wave functions obtained with the CIV3 (Configuration-Interaction Version 3) computer code of Hibbert. The important relativistic effects in intermediate coupling are incorporated by means of the Breit–Pauli Hamiltonian, which consists of the nonrelativistic term plus the one-body mass correction, Darwin term, and spin–orbit, spin–other-orbit, and spin–spin operators. To keep our calculated energy splittings as close as possible to the experimental values (wherever available), we have made small adjustments to the diagonal elements of the Hamiltonian matrices. Our calculated excitation energies, including their ordering, are in excellent agreement with the available experimental results. From our radiative decay rates we have also calculated radiative lifetimes of some fine-structure levels. The mixing among several fine-structure levels is found to be so strong that the correct identification of these levels becomes very difficult. We believe that our extensive calculations will be useful to experimentalists in identifying the fine-structure levels in their future work. In this calculation we also predict new data for several fine-structure levels where no other theoretical and (or) experimental results are available.

Atomic structure and radiative properties of He-like Ni26+ ion in dense plasma

2021 ◽  
Author(s):  
Mayank Dimri ◽  
Dishu Dawra ◽  
A.K. Singh ◽  
Alok K.S. Jha ◽  
Rakesh Kumar Pandey ◽  
...  
Keyword(s):  
Quantum Number ◽  
Transition Probabilities ◽  
Principal Quantum Number ◽  
Model Potential ◽  
Oscillator Strengths ◽  
Radiative Properties ◽  
Configuration Interaction Method ◽  
Excitation Energies ◽  
Plasma Energy ◽  
Plasma Background

The influence of plasma screening on the excitation energies and transition properties of He-like Ni<sup>26+</sup> ion under strongly coupled plasma background has been analyzed. To perform the analysis, the multiconfiguration Dirac-Fock method has been adopted by incorporating the ion sphere model potential as a modified interaction potential between the electron and the nucleus. For comparison purposes, parallel calculations have been carried out using the modified relativistic configuration interaction method. It is found that the plasma energy shifts corresponding to principal quantum number conserving transitions (Δ n = 0) are blue shifted, whereas red shifted for the transitions where the principal quantum number is not conserved (Δn ≠ 0). The variation of transition probabilities and weighted oscillator strengths with free electron densities has also been studied. The present results should be advantageous in the modeling and diagnostics of astrophysical and laboratory plasmas.

Energy levels and radiative transitions of the K-shell excited sextet states in boron-like sulfur ion

2016 ◽  
Vol 94 (10) ◽  
pp. 1054-1060 ◽  
Author(s):  
Yan Sun ◽  
CuiCui Sang ◽  
KaiKai Li ◽  
XinYu Qian ◽  
Feng Hu ◽  
...  
Keyword(s):  
Fine Structure ◽  
Relativistic Effect ◽  
Transition Probabilities ◽  
Theoretical Calculations ◽  
Energy Levels ◽  
Oscillator Strengths ◽  
Variation Method ◽  
First Order ◽  
Radiative Transitions ◽  
First Order Perturbation

Theoretical calculations are reported for energy levels and transition probabilities of the K-shell excited sextet series 6Se,o(m) and 6Po,e(m) (m = 1–7) for the astrophysically important element sulfur. Energy levels, fine structure splittings, and transition parameters of the high-lying sextet series 6Se,o(m) and 6Po,e(m) (m = 1–7) in boron-like sulfur ion are calculated with the multi-configuration Rayleigh–Ritz variation method. To obtain the accurate energy level, the relativistic corrections and mass polarization effect are included by using the first-order perturbation theory. Configuration structures of these sextet series are assigned according to the energies, percentage contributions of basis states to the eigenvector, relativistic effect corrections, and verification of fine structure splittings. The oscillator strengths, transition probabilities, and wavelengths of electric-dipole transitions between 6So,e(m) and 6Pe,o(m) (m = 1–7) states are also systematically calculated and discussed.

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.

Messung der Energiebreiten von Röntgen-Niveaus mit Hilfe der Auger-Elektronenspektroskopie

1968 ◽  
Vol 23 (2) ◽  
pp. 287-294 ◽  
Author(s):  
W. Mehlhorn ◽  
D. Stalherm ◽  
H. Verbeek
Keyword(s):  
Fine Structure ◽  
Transition Probabilities ◽  
Transition Probability ◽  
Level Width ◽  
Experimental Transition ◽  
Absolute Transition ◽  
Good Agreement

From the Auger transitions KL2,3L2,3(1D2) of neon and L3M2,2M2,3 (1D2) of argon the level widths Γ(K) of neon and Γ (L3) and Γ (L2) of argon have been determined by folding Lorentzian distributions with the spectrometer function. The values found are: Γ(K) = (0.15 ± 0.03) eV, Γ (L3) = Γ (L2) = (0.16 ± 0.02) eV. From the level width Γ(Κ) of neon and the relative intensities of the KLL Auger lines of neon, determined very recently, absolute transition probabilities of the KLL Auger transitions of neon have been calculated to be (in units of 10-3 e2/ħ a0=4.1 · 1013 sec-1) :KL1L1(1S0) = 0.35 ± 0.07;KL1L2,3 (1P1) = 0.96 ± 0.19;KL1L2,3 (2P) = 0.35 ± 0.07;KL2,3L2,3,3 (1S0) = 0.55 ± 0.11;KL2,3L2,3 (1D2) = 3.28 ± 0.66;KL2,3L2,3 (3P0,2) = 0 .Whereas the experimental total transition probability KLL is in good agreement with theoretical values of the transition probability for Ζ=10, determined by extrapolation of Callan’s values for Ζ ≧ 12 and of Archard’s values for Z=11, 12, 15, 16, 17, 18, the experimental transition probabilities of the fine structure components do not agree with Callan’s values and agree only in some cases with Archard’s values.

Multiconfigurational Dirac–Fock energy levels and radiative rates for Ni XXI

2014 ◽  
Vol 92 (11) ◽  
pp. 1285-1296 ◽  
Author(s):  
Sunny Aggarwal ◽  
Nupur Verma ◽  
A.K. Singh ◽  
Narendra Singh ◽  
Rinku Sharma ◽  
...  
Keyword(s):  
Transition Probabilities ◽  
Transition Probability ◽  
Energy Levels ◽  
Oscillator Strengths ◽  
Fusion Plasmas ◽  
Transition Wavelength ◽  
Forbidden Transitions ◽  
New Energy ◽  
Atomic Structure Calculations ◽  
Structure Calculations

We present accurate atomic structure calculations for the lowest 200 fine structural energy levels for oxygen-like nickel, which may be a useful ion for both astrophysical and fusion plasmas. For the calculations of energy levels and radiative rates, we have used the multiconfigurational Dirac–Fock method. Our results are compared with those obtained using other numerical methods and experiments so that their accuracy can be assessed. The transition wavelengths, oscillator strengths, and radiative rates are reported for electric dipole (E1) transitions from the ground state. We have also presented the transition probabilities and transition wavelength of some forbidden transitions. Finally, we predict new energy levels, oscillator strengths, and transition probability data, where no other theoretical or experimental results are available, which may be useful for future experimental work.

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