The effect of configuration interaction on forbidden line strengths

1956 ◽  
Vol 52 (1) ◽  
pp. 107-113 ◽  
Author(s):  
R. H. Garstang
Keyword(s):  
Configuration Interaction ◽  
Major Part ◽  
Energy Levels ◽  
Line Strength ◽  
Line Strengths

ABSTRACTThe calculation of the strengths of forbidden lines in the 1s22s22p2 configuration is extended to include the effect of interaction with the 1s22p4 configuration. For this case it is shown that if observed energy levels are used instead of theoretical energies in line-strength formulae which neglect configuration interaction the major part of the effect of configuration interaction is nevertheless taken into account. The results are illustrated by detailed computations on the Ca xv spectrum. The 1s22s22p4 configuration is also discussed.

scholarly journals Line-Strength Gradients in Early-Type Galaxies

1987 ◽  
Vol 127 ◽  
pp. 189-202
Author(s):  
J. Gorgas ◽  
G. Efstathiou
Keyword(s):  
Globular Clusters ◽  
Line Strength ◽  
Early Type ◽  
Metallic Line ◽  
Total Luminosity ◽  
Galactic Globular Clusters ◽  
Measured Line ◽  
Line Strengths

We have measured line-strength gradients in a sample of 15 early-type galaxies. The line-strength measures include the Mg2 index and the equivalent widths of Hβ and two iron blends at 5270Å and 5335Å. In most of the galaxies we find gradients in the metallic line-strengths. However, the gradients vary markedly from object to object and do not correlate strongly with other parameters such as total luminosity, rotation, etc. A comparison of the line-strengths in the outer parts of these galaxies with galactic globular clusters suggests relatively modest abundance gradients in early-type galaxies.

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.

Experimental Determination of Line Strengths for Selected Carbon Monoxide and Carbon Dioxide Absorption Lines at Temperatures between 295 and 1250 K

1994 ◽  
Vol 48 (11) ◽  
pp. 1442-1450 ◽  
Author(s):  
Patrick J. Medvecz ◽  
Kenneth M. Nichols
Keyword(s):  
Fourier Transform ◽  
High Temperature ◽  
Absorption Spectra ◽  
High Temperatures ◽  
Room Temperature ◽  
Theoretical Calculations ◽  
Line Strength ◽  
Temperature Data ◽  
Line Strengths

Fourier transform infrared absorption spectroscopy has been used for the determination of the line strengths of 41 CO and CO2 absorption lines at temperatures between 295 and 1250 K. The CO vibrational-rotational lines were from the P branch of the fundamental absorption band (2150–1950 cm−1) while the CO2 vibrational-rotational lines were from the far wing of the R branch of the v3 fundamental band (2395–2380 cm−1). The intensities of the lines were measured from absorption spectra recorded in a high-temperature gas cell containing known concentrations of CO/CO2/N2 gas mixtures at atmospheric pressure. Absorption spectra were recorded through the cell with the use of a moderate-resolution Fourier transform infrared spectrometer. The absorption spectra were mathematically corrected for distortions resulting from the finite resolution of the spectrometer and for peak overlap. Line strength measurements were made from the corrected peaks by using the Bouguer-Lambert law and assuming a Lorenztian line profile. The experimentally obtained line strengths were evaluated (1) by statistical calculations, (2) by consideration of the validity of the Bouguer-Lambert assumption for these data, (3) by comparison with existing room-temperature and high-temperature data, and (4) by comparison with theoretical calculations. For CO, the statistical analysis suggests that the reported values have an uncertainty of ±10–12%, which is similar to the observed discrepancies with other reported values at room temperature. At high temperatures, the difference between these data and previously reported data and theoretical predictions is less than 10%. For CO2, the statistical uncertainty associated with the line strength calculations is less than 5%, which is also the approximate level of agreement with existing room-temperature data. For lines with m indicies of 65–89, at high temperatures, the values reported in this work agree within 5 to 10% of theoretical calculations.

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.

Spectra, energy levels, and transition line strengths forSm3+:Y3Al5O12

1999 ◽  
Vol 60 (23) ◽  
pp. 15643-15653 ◽  
Author(s):  
John B. Gruber ◽  
Bahram Zandi ◽  
Michael F. Reid
Keyword(s):  
Energy Levels ◽  
Transition Line ◽  
Line Strengths

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.

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