Relativistic effects on the hyperfine structures of 2 p(4)(P-3)3 p D-2(o), D-4(o), and P-4(o) in F-19 I

The hyperfine interaction constants of the 2p(4)(P-3)3p D-2(3/2,5/2)o, D-4(1/2-7/2)o, and P-4(1/2-5/2)o levels in neutral fluorine are investigated theoretically. Large-scale calculations are carried out using the multiconfiguration Hartree-Fock (MCHF) and Dirac-Hartree-Fock (MCDHF) methods. In the framework of the MCHF approach, the relativistic effects are taken into account in the Breit-Pauli approximation using nonrelativistic orbitals. In the fully relativistic approach, the orbitals are optimized using the Dirac-Coulomb Hamiltonian with correlation models inspired by the nonrelativistic calculations. Higher-order excitations are captured through multireference configuration interaction calculations including the Breit interaction. In a third (intermediate) approach, the Dirac-Coulomb-Breit Hamiltonian matrix is diagonalized in a relativistic configuration space built with nonrelativistic MCHF radial functions converted into Dirac spinors using the Pauli approximation. The magnetic dipole hyperfine-structure constants calculated with the three relativistic models are consistent and reveal unexpectedly large effects of relativity for 2D(5/2)(o), P-4(3/2)o, and P-4(5/2)o. The agreement with the few available experimental values is satisfactory. The strong J dependence of relativistic corrections on the hyperfine constants is investigated through the detailed analysis of the orbital, spin-dipole, and contact relative contributions calculated with the nonrelativistic magnetic dipole operator

Isotope shift in the electron affinity of beryllium

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Theoretical Study of the Hyperfine Structure and Isotope Shifts in Near-Infrared Transitions of Atomic Nitrogen

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Theoretical evaluation of the Be- 2s2p² 4P hyperfine parameters and Be 2s2p ³Po electron-affinity

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Theoretical evaluation of the 7,9Be- 2s2p² 4P1/2,3/2,5/2 hyperfine structure parameters and Be 2s2p ³Po electron-affinity

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Theoretical evaluation of the 7,9 Be- 2s2p² 4P_1/2,3/2,5/2 hyperfine structure parameters and Be 2s2p ²Po electron-affinity

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Theoretical hyperfine structures of F 19 i and O 17 i

Multiconfiguration Hartree-Fock (MCHF) and multiconfiguration Dirac-Hartree-Fock (MCDHF) calculations are performed for the 2p5Po2, 2p4(3P)3s4P, 2p4(3P)3s2P, and 2p4(3P)3p4So states of F19 i to determine their hyperfine constants. Several computing strategies are considered to investigate electron correlation and relativistic effects. High-order correlation contributions are included in MCHF calculations based on single and double multireference expansions. The largest components of the single reference MCHF wave functions are selected to define the multireference (MR) sets. In this scheme, relativistic corrections are evaluated in the Breit-Pauli approximation. A similar strategy is used for the calculation of MCDHF relativistic wave functions and hyperfine parameters. While correlation and relativistic corrections are found to be rather small for the ground state, we highlight large relativistic effects on the hyperfine constant A3/2 of 2p4(3P)3p4So and, to a lesser extent, on A1/2 of 2p4(3P)3s4P. As expected for such a light system, electron correlation effects dominate over relativity in the calculation of the hyperfine interaction of all other levels considered. We also revisit the hyperfine constants of 2p3(4S)3sSo5 and 2p3(4S)3p5P in O17 using similar strategies. The results are found to be in excellent agreement with experiment.SCOPUS: ar.jinfo:eu-repo/semantics/publishe

Ab initio calculations of 14N and 15N hyperfine structures

Hyperfine structure parameters are calculated for the 2p2(3P)3s 4PJ, 2p2(3P)3p 4Po J and 2p2(3P)3p 4Do J levels, using the ab initio multiconfiguration Hartree–Fock method. The theoretical hyperfine coupling constants are in complete disagreement with the experimental values of Jennerich et al deduced from the analysis of the near-infrared Doppler-free saturated absorption spectra

Hyperfine structure of near-infrared transitions in neutral nitrogen revisited

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