Atomic Negative Ions: The Iron Series

Results of the Hartree-Fock calculations on the ground state for the ions ${\mathrm{K}}^{-}\left({}_{}{}^1{}_{}{}^{}S\right)$, ${\mathrm{Sc}}^{-}\left({}_{}{}^3{}_{}{}^{}F\right)$, ${\mathrm{Ti}}^{-}\left({}_{}{}^4{}_{}{}^{}F\right)$, ${\mathrm{V}}^{-}\left({}_{}{}^5{}_{}{}^{}D\right)$, $\mathrm{Cr}{2}^{-}\left({}_{}{}^6{}_{}{}^{}S\right)$, ${\mathrm{Mn}}^{-}\left({}_{}{}^5{}_{}{}^{}D\right)$, ${\mathrm{Fe}}^{-}\left({}_{}{}^4{}_{}{}^{}F\right)$, ${\mathrm{Co}}^{-}\left({}_{}{}^3{}_{}{}^{}F\right)$, ${\mathrm{Ni}}^{-}\left({}_{}{}^2{}_{}{}^{}D\right)$, and ${\mathrm{Cu}}^{-}\left({}_{}{}^1{}_{}{}^{}S\right)$ are reported. By first-order perturbation calculation on the Hartree-Fock functions, the relativistic energy has been computed. The relativistic and the Hartree-Fock energies now available, and the correlation energy of the corresponding neutral atoms, previously obtained, make it feasible to obtain accurate estimate of the electron affinities for the above series of negative ions. These are 0.92, -0.14, 0.40, 0.94, 0.98, -1.07, 0.58, 0.94, 1.28, 1.80 eV for ${\mathrm{K}}^{-}$, ${\mathrm{Sc}}^{-}$, ${\mathrm{Ti}}^{-}$, ${\mathrm{V}}^{-}$, ${\mathrm{Cr}}^{-}$, ${\mathrm{Mn}}^{-}$, ${\mathrm{Fe}}^{-}$, ${\mathrm{Co}}^{-}$, ${\mathrm{Ni}}^{-}$, and ${\mathrm{Cu}}^{-}$, respectively, for the states above indicated. The uncertainty on the above data is estimated to be from 0.1 to 0.35 eV.