A new module, RDENSITY, of the GRASP2018 package 1 is presented for evaluating the radial electron density function of an atomic state described by a multiconfiguration Dirac-Hartree-Fock or ...configuration interaction wave function in the fully relativistic scheme. The present module is the relativistic version of DENSITY 2 that was developed for the ATSP2K package 3. The calculation of the spin-angular factors entering in the expression of the expectation value of the density operator is performed using the angular momentum theory in orbital, spin, and quasispin spaces, adopting a generalized graphical technique 4. The natural orbitals (NOs) are evaluated from the diagonalization of the density matrix, taking advantage of its κ-block structure. The features of the code are discussed in detail, focusing on the advantages and properties of the NOs and on the electron radial density picture as a mean for investigating electron correlation and relativistic effects.
Program title:RDENSITY
CPC Library link to program files:https://doi.org/10.17632/4sdrf5kfzd.1
Licensing provisions: MIT license
Programming language: FORTRAN 95
Nature of problem: This program determines the atomic electron radial density in the MCDHF approximation. It also evaluates the natural orbitals by diagonalizing the density matrix.
Solution method: Building the density operator using second quantization - Spherical symmetry averaging - Evaluating the matrix elements of the one-body excitation operators in the configuration state function (CSF) space using the angular momentum theory in orbital, spin, and quasispin spaces.
Additional comments including restrictions and unusual features: We evaluated the electron radial density and natural orbitals of the lowest states in Mg II. The MCDHF wave functions consisted of four non-interacting blocks and a total of 79 000 CSFs. The calculation took around 2 minutes using a computer with an Intel(R) Xeon(R) Gold 6148 processor @ 2.4 GHz.
1GRASP2018 - A Fortran 95 version of the General Relativistic Atomic Structure Package, C. Froese Fischer, G. Gaigalas, P. Jönsson and J. Bieroń, Comput. Phys. Commun. 237 (2019) 184-187.2Multiconfiguration electron density function for the ATSP2K-package, A. Borgoo, O. Scharf, G. Gaigalas and M. Godefroid, Comput. Phys. Commun. 181 (2010) 426-4393An MCHF atomic-structure package for large-scale calculations, C. Froese Fischer, G. Tachiev, G. Gaigalas, and M. Godefroid, Comput. Phys. Commun. 176 (2007) 559-5794An efficient approach for spin-angular integrations in atomic structure calculations, G. Gaigalas, Z. Rudzikas, and C. Froese Fischer, J. Phys. B: At. Mol. Phys., 30 (1997) 3747-3771
In the present work, we report an investigation on the importance of using realistic partition functions in the opacity calculations of lanthanide ions whether they are moderately or lowly ionized. ...In order to do this, atomic data for various moderately charged samarium (Sm V–XI) and lowly charged neodymium (Nd II–IV) ions were calculated by the pseudo-relativistic Hartree–Fock method (HFR) and then, used to compute the expansion opacities for conditions characterizing the ejecta of kilonovae observed as a result of neutron star mergers, with a particular attention given to the partition function computations.
Graphical abstract
The changes in the mean-square charge radius (relative to 209Bi), magnetic dipole, and electric quadrupole moments of 187, 188, 189, 191Bi were measured using the in-source resonance-ionization ...spectroscopy technique at ISOLDE (CERN). A large staggering in radii was found in 187, 188, 189Big, manifested by a sharp radius increase for the ground state of 188Bi relative to the neighboring 187, 189Big. A large isomer shift was also observed for 188Bim. Both effects happen at the same neutron number, N = 105 , where the shape staggering and a similar isomer shift were observed in the mercury isotopes. Experimental results are reproduced by mean-field calculations where the ground or isomeric states were identified by the blocked quasiparticle configuration compatible with the observed spin, parity, and magnetic moment.
•Ab initio fully relativistic MCDHF calculations of isotope shift electronic parameters have been carried in neutral antimony.•Relativistic normal mass shift, specific mass shift and field shift ...electronic parameters are given for all the known fine-structure levels belonging to the even 5p26sJ=1/2−3/2 and the odd {5p3+5p26p+5p27p}J=1/2−5/2 configurations of Sb I and for E1 transitions involving them.•Comparison with the two sets of experimental line isotope shifts shows 4,5 a good agreement with our MCDHF predictions for the most recent measurements by Sobolewski et al. 5 but does not allows us to reject the old values of Buchholz et al. 4 for 5p3−5p26s, although striking differences are seen, due to the large uncertainty affecting the change in mean-square nuclear radius between the two stable isotopes 3.
Ab initio multiconfiguration Dirac–Hartree–Fock (MCDHF) calculations have been carried out in order to determine the isotope shift (IS) electronic parameters of transitions belonging to electric dipole (E1) transition arrays 5s25p3−5s25p26s,5s25p26s−5s25p26p and 5s25p26s−5s25p27p in neutral antimony, Sb I. In a correlation model limited to single and double excitations from the valence shells, these parameters, combined with the changes in mean-square nuclear charge radius δ⟨r2⟩123,121 compiled by Angeli and Marinova 3 produce isotope shifts values in good agreement with the most recent measurements by high-resolution emission and optogalvanic absorption spectroscopy of Sobolewski et al. 5 but not with the old measurements of Buchholz et al. 4 for 5p3−5p26s. However, our analysis does not allow to reject the latter due to the large uncertainty affecting δ⟨r2⟩123,121, i.e. 0.072 ± 0.048 fm2 3. This shows the need of a more accurate determination of this nuclear parameter. Although improving excitation energies, the inclusion of core-valence correlation limited to one hole in the 4d core subshell destroyed the theory-experiment agreement on the IS parameters.
The hyperfine structure constants for the ground 4s24p 2P°3/2 and lowest excited states 4s25s 2S1/2 of 71Ga are calculated using the GRASP2K package based on the multi-configuration ...Dirac-Hartree-Fock method. Furthermore, the magnetic dipole (μ) and the electric quadrupole (Q) moments of the Ga isotopes from 67Ga to 81Ga are derived.
Energy levels, normal and specific mass shift parameters as well as electronic densities at the nucleus are reported for numerous states along the beryllium, boron, carbon, and nitrogen isoelectronic ...sequences. Combined with nuclear data, these electronic parameters can be used to determine values of level and transition isotope shifts. The calculation of the electronic parameters is done using first-order perturbation theory with relativistic configuration interaction wavefunctions that account for valence, core–valence, and core–core correlation effects as zero-order functions. Results are compared with experimental and other theoretical values, when available.
Extended Calculations of Spectroscopic Data Wang, Kai; Jönsson, Per; Ekman, Jörgen ...
The Astrophysical journal. Supplement series,
04/2017, Letnik:
229, Številka:
2
Journal Article
Recenzirano
Odprti dostop
Employing two state-of-the-art methods, multiconfiguration Dirac-Hartree-Fock and second-order many-body perturbation theory, the excitation energies and lifetimes for the lowest 200 states of the 2 ...s(2)2p(4), 2s2p(5), 2p(6), 2s(2)2p(3)3s, 2s(2)2p(3)3p, 2s(2)2p(3)3d, 2s(2)p(4)3s, 2s2p(4)3p, and 2s2p(4)3d configurations, and multipole (electric dipole (E1), magnetic dipole (M1), and electric quadrupole (E2)) transition rates, line strengths, and oscillator strengths among these states are calculated for each O-like ion, from Cr XVII to Zn XXIII. Our two data sets are compared with the National Institute of Standards and Technology and CHIANTI compiled values, and previous calculations. The data are accurate enough for identification and deblending of new emission lines from the Sun and other astrophysical sources. The amount of high-accuracy data is significantly increased for the n. =. 3 states of several O-like ions of astrophysical interest, where experimental data are very scarce.
Hyperfine structure (HFS) measurements of neutron-rich iridium isotopes Ir196,197,198 (Z=77,N=119-121) were performed via in-gas-cell laser resonance ionization spectroscopy at the KEK Isotope ...Separation System. Magnetic dipole moments μ and isotope shifts were determined from the HFS spectra. The variation of mean-square charge radii and quadrupole deformation parameters of these isotopes were evaluated from the isotope shifts. The μ value of Ir197 agreed with a theoretical value based on the strong coupling model, and the Ir nucleus was interpreted as prolately deformed by the theoretical calculations. The μ values of Ir196,198 were also compared with semiempirical values calculated based on the strong coupling model. From the comparison, we can suggest the possible spin values of Iπ=1,2- for Ir196 and Iπ=1- for Ir198.
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