The embedded cluster method was used to calculate the electronic structure of the F-center in NaCl, and of the pure anion vacancy, and F+ and F-centers, in MgO. The main features of the model were a self-interactive correction of single-particle energies in the case of perfect crystals, and point defects whose states were in the band-gap of a perfect crystal. A Mott-Littleton modification permitted an analytical description of the defect wave function.

A.B.Sobolev: Radiation Effects and Defects in Solids, 1995, 134, 51-5