Large scale multi-configuration Hartree-Fock calculation of the hyperfine structure of the ground state of vanadium

Open Physics ◽  
2006 ◽  
Vol 4 (1) ◽  
pp. 42-57
Author(s):  
Oliver Scharf ◽  
Gediminas Gaigalas

AbstractThe hyperfine structure of the ground state of vanadium, 51VI, is calculated in the nonrelativistic framework of the multi-configuration Hartree-Fock approximation. A configuration state function limiting algorithm is used to make the calculations feasible and to study the influence of core, valence and core-valence correlations in detail. The obtained configuration state function space captures the most important orbital correlations within 2%. Further correlations are included through configuration interaction calculation. The atomic state functions are used to evaluate the magnetic dipole hyperfine factor A and the electric quadrupole factor B. It turns out that the ab initio calculation can not capture the core polarization of the 2s shell. It introduces an error that is higher than the Hartree-Fock approximation. However, the detailed correlations being observed suggest the introduction of a wrong correlation orbital due to the algorithm being used. Neglecting this orbital leads to good agreement with 2% deviation from the experimental values for the A factors.

2016 ◽  
Vol 94 (4) ◽  
pp. 359-364 ◽  
Author(s):  
Miao Wu ◽  
Guojie Bian ◽  
Xiangfu Li ◽  
Min Xu ◽  
Quanping Fan ◽  
...  

The multi-configuration Dirac–Hartree–Fock method and active space approach are used to investigate the energy levels, hyperfine structure constants, and transition probabilities of a neutral silicon atom. The contributions of Breit interactions and quantum electrodynamics correction are considered. Compared with other theoretical and experimental values of energy levels, our values are in good agreement; the discrepancies of the majority of energy levels calculated are within 1% of experimental values, and the energy levels calculated are very close to other theoretical values. The number of energy levels we considered is larger than that of any other theoretical calculations. The values of the hyperfine structure constant A of the radioactive 29Si atom that we calculated are in good agreement with experimental values. From these results we can predict the hyperfine structure constant A of other states of 29Si where no other theoretical results are available. The transition probabilities of neutral silicon have also been calculated and discussed.


2007 ◽  
Vol 21 (13n14) ◽  
pp. 2204-2214 ◽  
Author(s):  
BEATE PAULUS

The method of increments is a wavefunction-based ab initio correlation method for solids, which explicitly calculates the many-body wavefunction of the system. After a Hartree-Fock treatment of the infinite system the correlation energy of the solid is expanded in terms of localised orbitals or of a group of localised orbitals. The method of increments has been applied to a great variety of materials with a band gap, but in this paper the extension to metals is described. The application to solid mercury is presented, where we achieve very good agreement of the calculated ground-state properties with the experimental data.


2014 ◽  
Vol 69 (8-9) ◽  
pp. 397-402
Author(s):  
Leyla Özdemir ◽  
Sadiye Tuna

We have investigated the correlation, relativistic, and isotope shift effects on the fine structure levels in the ground state configuration for the antimony anion ( Sb-). Energies and radiative transition probabilities (for magnetic dipole, M1, and electric quadrupole, E2) have been obtained using the multiconfiguration Hartree-Fock method within the framework of the Breit-Pauli Hamiltonian. Therefore, the most important configuration interaction and relativistic effects have been included. Comparisons with other available works are presented. For some M1 and E2 lines the considered transition probabilities are reported for the first time


Atoms ◽  
2020 ◽  
Vol 8 (2) ◽  
pp. 18 ◽  
Author(s):  
Pascal Quinet ◽  
Patrick Palmeri

The main purpose of the Database on Rare Earths At Mons University (DREAM) is to provide the scientific community with updated spectroscopic parameters related to lanthanide atoms (Z = 57–71) in their lowest ionization stages. The radiative parameters (oscillator strengths and transitions probabilities) listed in the database have been obtained over the past 20 years by the Atomic Physics and Astrophysics group of Mons University, Belgium, thanks to a systematic and extensive use of the pseudo-relativistic Hartree-Fock (HFR) method modified for taking core-polarization and core-penetration effects into account. Most of these theoretical results have been validated by the good agreement obtained when comparing computed radiative lifetimes and accurate experimental values measured by the time-resolved laser-induced fluorescence technique. In the present paper, we report on the current status and developments of the database that gathers radiative parameters for more than 72,000 spectral lines in neutral, singly-, doubly-, and triply-ionized lanthanides.


1967 ◽  
Vol 28 (1) ◽  
pp. 29-42 ◽  
Author(s):  
D. L. Turcotte ◽  
E. R. Oxburgh

A solution is obtained for steady, cellular convection when the Rayleigh number and the Prandtl number are large. The core of each two-dimensional cell contains a highly viscous, isothermal flow. Adjacent to the horizontal boundaries are thin thermal boundary layers. On the vertical boundaries between cells thin thermal plumes drive the viscous flow. The non-dimensional velocities and heat transfer between the horizontal boundaries are found to be functions only of the Rayleigh number. The theory is used to test the hypothesis of large scale convective cells in the earth's mantle. Using accepted values of the Rayleigh number for the earth's mantle the theory predicts the generally accepted velocity associated with continental drift. The theory also predicts values for the heat flux to the earth's surface which are in good agreement with measurements carried out on the ocean floors.


1972 ◽  
Vol 50 (11) ◽  
pp. 1169-1174 ◽  
Author(s):  
C. E. Tull ◽  
M. Jackson ◽  
R. P. McEachran ◽  
M. Cohen

Theoretical multiplet strengths for electric quadrupole transitions between 2S, 2P0, 2D, and 2F0 levels of Na I, Mg II, and Al III have been calculated using Hartree–Fock wave functions of frozen-core type. The resulting 2S–2D oscillator strengths for Na I are in good agreement with calculations by Bogaard and Orr, Boyle and Murray, and Warner; however, for Mg II there is a discrepancy of a factor of 2 between our results and those of Warner.


1993 ◽  
Vol 07 (01n03) ◽  
pp. 38-41 ◽  
Author(s):  
R. J. RADWAŃSKI ◽  
J. J. M. FRANSE

Particularities in the specific heat of UPd 2 Al 3, a λ-type of peak with a maximum at 14.5 K and a Schottky-type of peak with a broad maximum at 55 K, has been attributed to the 5f-subsystem of the U atoms. The U-5f contribution has been found to be described surprisingly well within a single-ion Hamiltonian that includes the charge multipolar (CMP) interactions and the antiferromagnetic (AF) exchange interaction between the U 3+ ions. The AF exchange parameter and the full set of the CMP parameters associated with the hexagonal symmetry have been evaluated. The energy-level scheme (ELS) of this Kramers ion is constructed. The ground-state function Γ8 of the 5f 3 electrons is highly anisotropic. This state results from higher-order charge multipolar interactions. Magnetic properties resulting from this scheme including the metamagnetic-like transition at 18 T, the strongly-reduced value for the U-ion moment and its field dependence are found to be in good agreement with experimental observations.


A theoretical analysis is made of the hyperfine structure of the twelve levels of Eu I 4 f 7 ( 8 S ) 6 s 6 p using intermediate-coupled eigenfunctions obtained from a least-squares fit of the energies of the levels. Relativistic effects for the 6 p electron are calculated throughout by tensor-operator techniques. Good agreement is obtained with the observed A values, treating as parameters the polarization of the core (by the f electrons) and the hyperfine interaction constant of the 6 s electron. The magnitude of the core polarization is related to data on Eu I 4 f 7 ( 8 S ) 6s 2 , Euii 4 f 7 ( 8 s ) 6 s , and Eu III 4 f 7 ( 8 S ). The hyperfine-structure anomalies also fall into a consistent pattern. The observed B values are related to quadrupole moments of 151 Eu and 153 Eu.


2016 ◽  
Vol 31 (28) ◽  
pp. 1650162 ◽  
Author(s):  
H. C. Manjunatha ◽  
B. M. Chandrika ◽  
L. Seenappa

A new empirical formula is proposed for mass excess of heavy and superheavy nuclei in the region Z = 96–129. The parameters of the formula are obtained by making a polynomial fit to the available theoretical and experimental data. The calculated mass excess values are compared with the experimental values and other results of the earlier proposed models such as finite range droplet model (FRDM) and Hartree–Fock–Bogoliubov (HFB) method. Standard deviation of calculated mass excess values for each atomic number is tabulated. The good agreement of present formula with the experiment and other models suggests that the present formula could be used to evaluate the mass excess values of heavy and superheavy nuclei in the region 96[Formula: see text][Formula: see text][Formula: see text]Z[Formula: see text][Formula: see text][Formula: see text]129. This formula is a model-independent formula and is first of its kind that produces a mass excess values with the only simple inputs of only Z and A.


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