Defect properties of ionic solids. II. Point defect energies based on modified electron-gas potentials

Abstract

For pt.I see ibid., vol.10, no.9, p.1431 (May 1977). A modified form of the electron-gas approximation is proposed for the calculation of interionic potentials in the solid state. On the basis of these potentials perfect lattice and defect properties of a number of solids are calculated and compared both with experiment and with the results derived from other theoretical methods. The cohesive energies, lattice constants and compressibilities of a wide range of oxides are considered, while the defect energies for NaCl, MgO, MnO, CaF2 and MgF2 are examined in detail. From the results presented it is concluded that for solids such as the alkali and alkaline-earth halides and the alkaline-earth oxides, which are largely ionic, the modified electron-gas approximation is a reliable non-empirical method for the calculation of interionic potentials.