Relativistic Self-Consistent-Field Calculations of the Magnetic Dipole and Electric Quadrupole Hyperfine Structure in the 4d- and 5d- Shell Atoms

Relativistic and non-relativistic self-consistent-field (SCF) wavefunctions using the restricted Hartree-Fock scheme as well as SCF methods with statistical exchange have been obtained for the nd N ( n + 1) s 2 , nd N +1 ( n + 1) s and nd N +2 configurations (with n = 4, 5) of the 4 d and 5 d shell atoms. The mean value of r -3 for the valence d electrons and the electron density at the nucleus for the valence s electrons have been evaluated with the non-relativistic wavefunctions. Effective radial hyperfine integrals for the magnetic dipole and electric quadrupole interaction have been evaluated using the relativistic wavefunctions. These theoretical hyperfine integrals for the magnetic dipole interaction are compared with experimental values. For the quadrupole interaction the radial integrals have been used for the evaluation of quadrupole moments from experimentally determined hyperfine parameters. The moments evaluated from the pure relativistic quadrupole parameters are associated with big uncertainties due to bad accuracy of the experimentally derived ones. An estimate of the quadrupole shielding (Sternheimer correction factor) has been obtained for some elements by a comparison of moments derived in this work and from hyperfine data in muonic and pionic atoms.