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.

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.

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.

scholarly journals Ab initio spin-free-state-shifted spin-orbit configuration interaction calculations on singly ionized iridium

1998 ◽  
Vol 108 (19) ◽  
pp. 7980-7987 ◽  
Author(s):  
Frank Rakowitz ◽  
Marcos Casarrubios ◽  
Luis Seijo ◽  
Christel M. Marian
Keyword(s):  
Ab Initio ◽  
Configuration Interaction ◽  
Free State ◽  
Spin Orbit ◽  
Configuration Interaction Calculations

Calculation of Wavelengths, Transition Probabilities and Oscillator Strengths for E1 and M1 Transitions in Cu-Like Au Ion

2015 ◽  
Vol 723 ◽  
pp. 799-803
Author(s):  
Min Xu
Keyword(s):  
Excited States ◽  
Magnetic Dipole ◽  
Configuration Interaction ◽  
Electric Dipole ◽  
Transition Probabilities ◽  
Energy Levels ◽  
Oscillator Strengths ◽  
Forbidden Transitions ◽  
Calculation Results ◽  
Good Agreement

Wavelengths, transition probabilities and oscillator strengths have been calculated for electric dipole (E1) transitions and magnetic dipole (M1) transitions in Cu-like Au ion. These values are obtained in the configuration interaction (CI) and using the fully relativistic multiconfiguration Dirac-Fock (MCDF) method including quantum electrodynamical (QED) effect and Breit correction. Obtained energy levels of some excited states in Cu-like Au ion from the method are generally in good agreement with valuable theoretical and experimental results. The calculation results indicate that for high-Z highly ionized atom, some forbidden transitions are very important.

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.

Blue absorption and red emission of Bi2+ in solids: strongly spin–orbit coupled 6p levels in low symmetry fields

2014 ◽  
Vol 16 (32) ◽  
pp. 17305-17314 ◽  
Author(s):  
Luis Seijo ◽  
Zoila Barandiarán
Keyword(s):  
Ab Initio ◽  
Radiative Lifetime ◽  
Orbit Coupling ◽  
Oscillator Strengths ◽  
High Symmetry ◽  
Spin Orbit Coupling ◽  
Spin Orbit ◽  
Red Emission ◽  
Confinement Potential ◽  
Low Symmetry

Ab initio calculations on a (BiO8)14− cluster under the effects of a high symmetry Oh confinement potential are used to study the energies of the 2P1/2, 2P3/2(1), and 2P3/2(2) spin–orbit coupling levels of the 6s26p configuration of Bi2+ in Oh, D4h, D2h, D4, D2d, D2, S4, C4v, C4, C3v, C2v, C2, Cs, and C1 fields, together with the 2P1/2 → 2P3/2(1) and 2P1/2 → 2P3/2(2) absorption oscillator strengths and the 2P3/2(1) radiative lifetime.

scholarly journals Full-Dimensional Ab Initio Potential Energy Surface and Vibrational Energy Levels of Li2H

Molecules ◽  
2018 ◽  
Vol 24 (1) ◽  
pp. 26
Author(s):  
Michiko Ahn Furudate ◽  
Denis Hagebaum-Reignier ◽  
Gwang-Hi Jeung
Keyword(s):  
Potential Energy ◽  
Potential Energy Surface ◽  
Ab Initio ◽  
Configuration Interaction ◽  
Energy Surface ◽  
Vibrational Energy ◽  
Energy Levels ◽  
Vibrational States ◽  
Configuration Interaction Method ◽  
Vibrational Energy Levels

We built a full-dimensional analytical potential energy surface of the ground electronic state of Li2H from ca. 20,000 ab initio multi-reference configuration interaction calculations, including core–valence correlation effects. The surface is flexible enough to accurately describe the three dissociation channels: Li (2s 2S) + LiH (1Σ+), Li2 (1Σg+) + H (1s 2S) and 2Li (2s 2S) + H (1s 2S). Using a local fit of this surface, we calculated pure (J = 0) vibrational states of Li2H up to the barrier to linearity (ca. 3400 cm−1 above the global minimum) using a vibrational self-consistent field/virtual state configuration interaction method. We found 18 vibrational states below this barrier, with a maximum of 6 quanta in the bending mode, which indicates that Li2H could be spectroscopically observable. Moreover, we show that some of these vibrational states are highly correlated already ca. 1000 cm−1 below the height of the barrier. We hope these calculations can help the assignment of experimental spectra. In addition, the first low-lying excited states of each B1, B2 and A2 symmetry of Li2H were characterized.

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