Lattice Energies of the Alkali Halides and the Electron Affinities of the Halogens

The overlap repulsion parameters that occur in the Born-Mayer treatment of lattice energies have been re-evaluated for the alkali halides from recent compressibility data. With these parameters the lattice energies of the alkali halides were calculated. The lattice energies were combined with thermochemical data to calculate the electron affinities of the halogens. The values obtained were: F 80.2; Cl 85.0; Br 79.5; and I 72.5 kcal/mole.