March 1, 1982
View Full PaperCalculated electron affinities of the elements
Key Points
- The aim is to calculate the electron affinities of ground-state negative ions for elements with atomic numbers less than 86.
- Used self-interaction correction to local spin-density approximation for calculations.
- Included analysis of relativistic contributions to electron affinities.
- Calculated ground-state densities for all neutral atoms and negative ions.
- Calculated electron affinity for Au increased from 1.5 eV to 2.5 eV due to relativistic effects.
- Certain rare earth elements, such as Ce and possibly Gd, are predicted to form stable negative ions.
- Doubly negative ions O²⁻ and Te²⁻ predicted to have no stable ground state.
Abstract
The extra-electron binding energies of the ground-state monatomic negative ions with Z<86 are calculated using the self-interaction correction (SIC) to the local spin-density approximation (LSD) for exchange and correlation. The results agree reasonably with experiment, and the errors reflect the familiar "interconfigurational energy error" common to LSD and SIC. Some of the rare earths, e. g. , Ce and possibly Gd, are predicted to form stable negative ions. In addition we have the following: (1) Relativistic (other than spin-orbit) contributions to the electron affinities are included and discussed. In Au the relativistic effects boost the calculated affinity from 1. 5 to 2. 5 eV. (2) The doubly negative ions O^2- and Te^2- are predicted to have no stable ground state. (3) Electron affinities are calculated for a few excited atomic states. (4) The calculated ground-state densities n (r) of all the neutral atoms and negative ions are monotonically decreasing functions of r. (5) Corrections to the random-phase-approximation electron-gas correlation energy are shown to cancel out of SIC calculations for atoms.