| 1. |
- Gaigalas, Gediminas, et al.
(författare)
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Energy Level Structure and Transition Data of Er2
- 2020
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Ingår i: Astrophysical Journal Supplement Series. - : Institute of Physics Publishing (IOPP). - 0067-0049 .- 1538-4365. ; 248:1
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Tidskriftsartikel (refereegranskat)abstract
- A majority of Er in the universe is synthesized by the r-process, which can occur in the mergers of neutron stars (NSs). The contribution of this element to the opacity of NS ejecta should be tested, but even the energy levels of first excited configuration have not been fully presented. The main aim of this paper is to present accurate energy levels of the ground [Xe]4f(12) and first excited [Xe]4f(11)5d configurations of Er2+. The energy level structure of the Er2+ ion was computed using the multiconfiguration Dirac-Hartree-Fock and relativistic configuration interaction (RCI) methods, as implemented in the GRASP2018 program package. The Breit interaction, self-energy, and vacuum polarization corrections were included in the RCI computations. The zero-first-order approach was used in the computations. Energy levels with the identification in LS coupling for all (399) states belonging to the [Xe]4f(12) and [Xe]4f(11)5d configurations are presented. Electric dipole (E1) transition data between the levels of these two configurations are computed. The accuracy of these data is evaluated by studying the behavior of the transition rates as functions of the gauge parameter, as well as by evaluating the cancellation factors. The core electron correlations were studied using different strategies. The rms deviations obtained in this study for states of the ground and excited configurations from the available experimental data are 649 and 754 cm(-1), respectively.
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| 2. |
- Gaigalas, Gediminas, et al.
(författare)
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Energy level structure of Er3+ free ion and Er3+ ion in Er2O3 crystal
- 2014
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Ingår i: National Institute for Fusion Science, Research Report NIFS-DATA. - : National Institute for Fusion Science. - 0915-6364. ; :115, s. 1-25
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Tidskriftsartikel (övrigt vetenskapligt/konstnärligt)abstract
- The latest version of the GRASP2K atomic structure package [P. J¨onsson, G. Gaigalas, J. Biero´n, C. Froese Fischer, I.P. Grant, Comput. Phys. Commun. 184 (2013) 2197], based on the multiconfigurational Dirac-Hartree-Fock method, is extended to account for effects of crystal fields in complex systems. Energies from relativistic configuration interaction calculations are reported for the Er3+ free ion. E2 and M1 line strengths, weighted oscillator strengths, and rates are presented for transitions between states of the [Xe]4f11 configuration. Also Stark levels of the Er3+ 4Io 15/2 state in Er2O3 are calculated in the ab initio point charge crystal field approximation. In all calculations the Breit interaction and leading QED effects are included as perturbations. Different strategies for describing electron correlation effects are tested and evaluated. The final results are compared with experiment and other methods.
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| 3. |
- Radziute, Laima, et al.
(författare)
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Energy level structure of Er3
- 2014
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Ingår i: Journal of Quantitative Spectroscopy and Radiative Transfer. - : Elsevier. - 0022-4073 .- 1879-1352. ; 152, s. 94-106
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Tidskriftsartikel (refereegranskat)abstract
- AtomicenergylevelsandE2andM1transitionratesarereportedforthe[Xe]4f11 ground configurationinEr3þ from relativisticmulticonfigurationDirac–Hartree–Fockandcon- figuration interactioncalculations.TheBreittransverseinteractionandleadingQED effectsareincludedasperturbations.Differentstrategiesfordescribingelectroncorrela- tion effectsaretestedandevaluated.Thecalculatedenergylevelsarecomparedwith experimentandresultsfromsemi-empiricalmethods.
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| 4. |
- Radziute, Laima, et al.
(författare)
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Energy level structure of Er3+ free ion
- 2014
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Ingår i: Ninth International Conference on Atomic and Molecular Data and Their Applications: book of abstracts. ; , s. 91-91
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Konferensbidrag (övrigt vetenskapligt/konstnärligt)abstract
- Ab initio calculations for the Er3+ ion are performed using GRASP2K package, based on multiconfigurational Dirac-Hartree-Fock method (MCDHF). 41 energy levels of the [Xe]4f 11 con- figuration are calculated. The study includes different types of correlations using different strategies. The Breit interaction and leading QED effects are included as perturbations in all calculations. We present the results of the 10 lowest levels (see Table 1), obtained by single and double excitations corresponding to valence, core, and core-valence correlations. Levels are notated in the form (2S+1)L Nr J , where instead of the group labels νW U, single character ”numbers” Nr are used. Deviation of our values for energy levels from NIST database reaches 6.9%. Energy levels given at NIST are derived from the spectrum of Er3+ in LaF3 [1].
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| 5. |
- Radziute, Laima, et al.
(författare)
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Energy level structure of the ground configuration in the Er3+ free ion
- 2015
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Ingår i: Physica Scripta. - : Bibliopolis, Edizioni di Filosofia e Scienze. - 0031-8949 .- 1402-4896. ; 90:5
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Tidskriftsartikel (refereegranskat)abstract
- Energy levels of the ground configuration [Xe]4f11 in the Er3+ ion are reported from relativistic configuration interaction calculations. Calculations are performed using the relativistic atomic structure package GRASP2K, which implements the multiconfiguration Dirac–Hartree–Fock method. The Breit transverse interaction and leading QED effects are included as perturbations. The final energies of 41 levels are compared with results from experiment and semi-empirical methods.
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