Relativistic effects on the hyperfine structures of 2p4(3P)3p 2Do, 4Do and 4Po in 19F I

Abstract

The hyperfine interaction constants of the 2p4(3P)3p 2Do_{3/2,5/2}, 4Do_{1/2-7/2} and 4Po_{1/2-5/2} 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 non relativistic orbitals. In the fully relativistic approach, the orbitals are optimized using the Dirac-Coulomb Hamiltonian with correlation models inspired by the non relativistic 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 non relativistic 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 2Do_{5/2}, 4Po_{3/2} and 4Po_{5/2}. 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 non relativistic magnetic dipole operator.