Relativistic oscillator strengths for np2 → np(n + 1)s transition array of SnI and PbI spectra in jj and intermediate coupling

1979 ◽  
Vol 57 (2) ◽  
pp. 147-151 ◽  
Author(s):  
J. Migdałek
Keyword(s):  
Transition Probabilities ◽  
Theoretical Data ◽  
Wave Functions ◽  
Oscillator Strengths ◽  
Intermediate Coupling ◽  
Hartree Fock ◽  
Semiempirical Approach ◽  
Exchange Effects ◽  
Relativistic Oscillator ◽  
Transition Array

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.

Theoretical oscillator strengths III. Transitions in Au I, Hg II, Pb IV, and Bi V spectra

1976 ◽  
Vol 54 (22) ◽  
pp. 2272-2278 ◽  
Author(s):  
J. Migdałek
Keyword(s):  
Theoretical Data ◽  
Relativistic Effects ◽  
Wave Functions ◽  
The Other ◽  
Oscillator Strengths ◽  
Semiempirical Approach ◽  
Calculated Line ◽  
Exchange Effects ◽  
Active Electron ◽  
Relativistic Oscillator

In the course of this investigation the relativistic oscillator strengths were calculated for some transitions in the principal, sharp, and diffuse series of the Au I, Hg II, Pb IV, and Bi V spectra. The radial integrals were computed employing the wave functions for the active electron obtained by a semiempirical approach which allowed for exchange effects. A comparison between the calculated line and multiplet f values and the other available experimental and theoretical data is presented. The influence of the relativistic effects on the oscillator strengths values for the transitions under consideration is discussed.

Theoretical oscillator strengths II. Transitions in principal, sharp, and diffuse spectral series of Al III, Ga III, In III, and Tl III spectra

1976 ◽  
Vol 54 (2) ◽  
pp. 130-136 ◽  
Author(s):  
J. Migdałek
Keyword(s):  
Theoretical Data ◽  
Relativistic Effects ◽  
Oscillator Strengths ◽  
Spectral Series ◽  
Semiempirical Approach ◽  
Exchange Effects ◽  
Optical Electron ◽  
Semiempirical Formula ◽  
Relativistic Oscillator ◽  
Good Agreement

A calculation is reported of nonrelativistic and relativistic oscillator strengths for the principal, sharp, and diffuse series, as well as some lifetimes, in the spectra of doubly ionized aluminum, gallium, indium and thallium. The wave functions that were used were obtained by employing a semiempirical approach which included exchange effects (the semiempirical [Formula: see text] method). Fairly good agreement was obtained with the available experimental and other theoretical data. A comparison of the nonrelativistic and relativistic oscillator strengths indicates that the influence of spin–orbit interaction of the optical electron, as well as other relativistic effects, is important in the case of even moderately heavy ions or atoms. Some systematic trends in the calculated oscillator strengths were found along the spectral series as well as along the sequence of homologous ions.

scholarly journals Recombination Spectra of Planetary Nebulae

1983 ◽  
Vol 103 ◽  
pp. 514-516
Author(s):  
P.O. Bogdanovich ◽  
Z.B. Rudzikas ◽  
T. H. Feklistova ◽  
A.F. Kholtygin ◽  
A.A. Nikitin ◽  
...  
Keyword(s):  
Transition Probabilities ◽  
Planetary Nebulae ◽  
Dielectronic Recombination ◽  
Wave Functions ◽  
Energy Spectra ◽  
Coupling Scheme ◽  
Intermediate Coupling ◽  
Hartree Fock ◽  
Radiative Transitions ◽  
Intermediate Coupling Scheme

The lines of the transitions between the subordinate levels of the CIII, NIII etc. ions are observed in the spectra of planetary nebulae (PN) (1). Their theoretical intensities may be found by solving the stationarity equations and accounting for both the recombination and cascade radiative transitions. It is possible to calculate the recombination spectra in various approaches: the single- or multi-configuration approximations (SCA and MCA) making use of both the superposition of configurations (SC) or the multiconfigurational Hartree-Fock-Jucys equations (2), taking into consideration the contribution of the dielectronic recombination to the intensities of the recombination lines. The energy spectra, the transition probabilities etc., as a rule ought to be calculated in the intermediate coupling scheme (2). Both analytical or numerical (e.g. Hartree-Fock) wave functions may be adopted.

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 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.

Electric Quadrupole Transitions in Na I, Mg II and Al III

1972 ◽  
Vol 50 (11) ◽  
pp. 1169-1174 ◽  
Author(s):  
C. E. Tull ◽  
M. Jackson ◽  
R. P. McEachran ◽  
M. Cohen
Keyword(s):  
Electric Quadrupole ◽  
Wave Functions ◽  
Oscillator Strengths ◽  
Hartree Fock ◽  
Good Agreement

Theoretical multiplet strengths for electric quadrupole transitions between 2S, 2P0, 2D, and 2F0 levels of Na I, Mg II, and Al III have been calculated using Hartree–Fock wave functions of frozen-core type. The resulting 2S–2D oscillator strengths for Na I are in good agreement with calculations by Bogaard and Orr, Boyle and Murray, and Warner; however, for Mg II there is a discrepancy of a factor of 2 between our results and those of Warner.

Inelastic Scattering of High Energy Electrons by Helium

1973 ◽  
Vol 51 (3) ◽  
pp. 311-315 ◽  
Author(s):  
S. P. Ojha ◽  
P. Tiwari ◽  
D. K. Rai
Keyword(s):  
Ground State ◽  
High Energy ◽  
Wave Functions ◽  
Oscillator Strengths ◽  
Final States ◽  
Interaction Type ◽  
Hartree Fock ◽  
High Energy Electrons ◽  
Approximate Wave ◽  
Accurate Wave

Generalized oscillator strengths and the cross section for excitation of helium by electron impact have been calculated in the Born approximation. Transitions from the ground state to the n1P (n = 2 and 3) states have been considered. Highly accurate wave functions of the Hartree–Fock and "configuration–interaction" type have been used to represent the ground state. Approximate wave functions due to Messmer have been employed for the final states. The results are compared with other calculations and with experiment.

Cancellation in the transition integrals for some dipole transitions: He isoelectronic series

1980 ◽  
Vol 58 (4) ◽  
pp. 546-548 ◽  
Author(s):  
Swadesh Kumar Ghoshal ◽  
Sankar Sengupta
Keyword(s):  
Confidence Level ◽  
Wave Functions ◽  
Oscillator Strengths ◽  
Isoelectronic Sequence ◽  
Hartree Fock ◽  
Isoelectronic Series

The amount of cancellation in the transition integrals for some np–n′d and nd–n′f singlet and triplet transitions for some members of helium isoelectronic sequence is estimated with Hartree–Fock wave functions. The results may act as a measure of the confidence level that can be attributed to the values of oscillator strengths of the respective cases.

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.

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