Atomic Negative Ions

Abstract

Results of Hartree-Fock calculations on the ions of ${\mathrm{Li}}^{\ensuremath{-}}$, ${\mathrm{B}}^{\ensuremath{-}}$, ${\mathrm{C}}^{\ensuremath{-}}$, ${\mathrm{N}}^{\ensuremath{-}}$, ${\mathrm{O}}^{\ensuremath{-}}$, ${\mathrm{F}}^{\ensuremath{-}}$, ${\mathrm{N}}^{\ensuremath{-}\ensuremath{-}}$, ${\mathrm{O}}^{\ensuremath{-}\ensuremath{-}}$ in states of the lowest electronic configuration, along with correlation and relativistic corrections, are given. These data are used to compute electron affinities for the atoms of the first row of the periodic table, and the stabilities of the excited states of the ions relative to the neutral atoms. Computed electron affinities for atoms on which experimental determinations are not available are 0.58\ifmmode\pm\else\textpm\fi{}0.05 eV for lithium, 0.3\ifmmode\pm\else\textpm\fi{}0.05 eV for boron, and -0.27\ifmmode\pm\else\textpm\fi{}0.11 eV for nitrogen. Computed electron affinities for other first row atoms are in agreement with experiment with the exception of oxygen, where the computed value of 1.22\ifmmode\pm\else\textpm\fi{}0.14 eV is significantly less than the experimental determination of 1.47 eV. For the first row atoms, no excited states of the ground-state electronic configuration are lower in energy than the neutral atom, although ${\mathrm{C}}^{\ensuremath{-}}(^{2}D)$ is only 0.08\ifmmode\pm\else\textpm\fi{}0.05 eV above.