Many-Body Calculation of Atomic Polarizability -Relation to Hartree-Fock Theory

Abstract

The Brueckner-Goldstone perturbation method has been applied to the calculation of the dipole polarizability (${\ensuremath{\alpha}}_{d}$) and antishielding factor (${\ensuremath{\gamma}}_{d}$) for lithium-atom ground state. The complete set of states utilized is the same as those employed in earlier calculations of the hyperfine constant and correlation energy. Our results are ${\ensuremath{\alpha}}_{d}=24.84$ ${\mathrm{\AA{}}}^{3}$ and ${\ensuremath{\gamma}}_{d}=0.958$, as compared to a recent experimental value for ${\ensuremath{\alpha}}_{d}=22\ifmmode\pm\else\textpm\fi{}2$ ${\mathrm{\AA{}}}^{3}$ and ${\ensuremath{\gamma}}_{d}=1.000$ from the Hellmann-Feynman theorem. The relationship between the Brueckner-Goldstone and the Hartree-Fock perturbation procedures is discussed with reference to specific physical effects.