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.

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.

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 relativistic oscillator strengths I. Transitions in principal, sharp, and diffuse series of Al I, Ga I, In I, and Tl I spectra

1976 ◽  
Vol 54 (2) ◽  
pp. 118-129 ◽  
Author(s):  
J. Migdałek
Keyword(s):  
Experimental Data ◽  
Excited States ◽  
Principal Series ◽  
Semiempirical Method ◽  
Oscillator Strengths ◽  
Relative Line ◽  
Exchange Effects ◽  
The One ◽  
Relativistic Oscillator ◽  
Good Agreement

The oscillator strengths for the sharp, principal, and diffuse series in the spectra of Al I, Ga I, In I, and Tl I are calculated as well as the lifetimes of their lowest excited states. The wave functions that were used were calculated by employing a relativistic semiempirical method which included exchange effects. Very good agreement with the most reliable experimental data was obtained for the fik values in the sharp series as well as for the calculated lifetimes. The discrepancies in the diffuse series are ascribed to the failure of the one-electron approach in the case of strongly perturbed series. The observed deviations in the relative line strengths from the values predicted neglecting the spin–orbit interaction were also investigated. Some systematic trends in the calculated oscillator strengths that were found for the sharp and principal series appear to be corroborated by experimental data for the sharp series in the spectra of Al I, Ga 1, In I.andTl 1.

Oscillator Strength Measurements in the Vacuum-Ultraviolet by the Emission Method

1988 ◽  
Vol 102 ◽  
pp. 353-356
Author(s):  
C. Goldbach ◽  
G. Nollez
Keyword(s):  
Oscillator Strength ◽  
Vacuum Ultraviolet ◽  
Oscillator Strengths ◽  
Emission Method ◽  
Absolute Scale ◽  
Good Agreement

AbstractThe principles and the realization of an experiment devoted to oscillator strength measurements in the vacuum-ultraviolet by the emission method are briefly presented. The results obtained for the strong multiplets of neutral nitrogen and carbon in the 1200-2000 Å range yield an absolute scale of oscillator strengths in good agreement with the most recent calculations.

Systematic calculations of energy levels and transitions rates in Mo XXVIII

2020 ◽  
Vol 75 (8) ◽  
pp. 739-747
Author(s):  
Feng Hu ◽  
Yan Sun ◽  
Maofei Mei
Keyword(s):  
Energy Levels ◽  
Oscillator Strengths ◽  
Atomic Data ◽  
Data Sets ◽  
Electron Systems ◽  
Excitation Energies ◽  
Experimental Values ◽  
Qed Effects ◽  
Hyperfine Structures ◽  
Good Agreement

AbstractComplete and consistent atomic data, including excitation energies, lifetimes, wavelengths, hyperfine structures, Landé gJ-factors and E1, E2, M1, and M2 line strengths, oscillator strengths, transitions rates are reported for the low-lying 41 levels of Mo XXVIII, belonging to the n = 3 states (1s22s22p6)3s23p3, 3s3p4, and 3s23p23d. High-accuracy calculations have been performed as benchmarks in the request for accurate treatments of relativity, electron correlation, and quantum electrodynamic (QED) effects in multi-valence-electron systems. Comparisons are made between the present two data sets, as well as with the experimental results and the experimentally compiled energy values of the National Institute for Standards and Technology wherever available. The calculated values including core-valence correction are found to be in a good agreement with other theoretical and experimental values. The present results are accurate enough for identification and deblending of emission lines involving the n = 3 levels, and are also useful for modeling and diagnosing plasmas.

Theoretical Investigations on Mechanical Stability and Electronic Structure of NbN under Pressures

2011 ◽  
Vol 90-93 ◽  
pp. 1264-1271
Author(s):  
Xiao Feng Li ◽  
Jun Yi Du
Keyword(s):  
Debye Temperature ◽  
Density Functional ◽  
Mechanical Stability ◽  
Structural Parameters ◽  
Theoretical Data ◽  
Hexagonal Structure ◽  
Functional Theory ◽  
Theoretical Investigations ◽  
Crystallographic Structures ◽  
Good Agreement

The ground structure, elastic and electronic properties of several phases of NbN are determined based on ab initio total-energy calculations within the framework of density functional theory. Among the five crystallographic structures that have been investigated, the hexagonal phases have been found to be more stable than the cubic ones. The calculated equilibrium structural parameters are in good agreement with the available experimental results. The elastic constants of five structures in NbN are calculated, which are in consistent with the obtained theoretical and experimental data. The corresponding Debye temperature and elastic ansitropies are also obtained. The Debye temperature of NbN in various structures consistent with available experimental and theoretical data, in which the Debye temperature of δ-NbN is highest. The anisotropies of ZB-NbN, NaCl-NbN, CsCl-NbN gradually increases. For hexagonal structure, the anisotropies of ε-NbN are stronger than that of δ-NbN. The electronic structures of NbN under pressure are investigated. It is found that NbN have metallization and the hybridizations of atoms in NbN under pressure become stronger.

Furan and Thiophene Analogs of Phenanthrene A Theoretical Study of the Absorption Spectra of Benzodifurans, Benzodithiophenes and Thienobenzofurans

1971 ◽  
Vol 26 (12) ◽  
pp. 1235-1240 ◽  
Author(s):  
L. Klasinc ◽  
J. V. Knop
Keyword(s):  
Absorption Spectra ◽  
Theoretical Study ◽  
Oscillator Strengths ◽  
Electron Transitions ◽  
Good Agreement ◽  
Lcao Mo

The LCAO -MO -SCF -CI method was applied to benzo(1,2-b : 4,3-b′) -difuran and -dithiophene, benzo (2,1-b : 3,4-b′) -difuran and -dithiophene, benzo (1,2-b : 3,4-b′) -difuran and -dithiophene, thieno (2,3-e) benzofuran, thieno (3,2-e) benzofuran, thieno (3,2-g) benzofuran, thieno (2,3-g) benzofuran, benzofuran, benzothiophene and phenanthrene. The calculated π-electron transitions and their oscillator strengths are in good agreement with known absorption spectra. The resemblance of these spectra to the absorption spectra of phenanthrene and phenanthrolines is discussed.

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