The local density of states and the local environment in alloys

The local density of states of a concentrated alloy can be calculated by an extension of the matching Green function method. This involves the inversion of a matrix with the form of tight binding between bonds. The method is applied to calculating the bandstructure and local density states of a square-well model of ordered LiMg. At low energies near the bottom of the band the local density of states is fairly uniform throughout the crystal, but at higher energies it approaches the bulk value for each atom. The relationship between this approach, which stresses the local environment, and nearly-free-electron perturbation theory is explained. Finally the implications of the work for soft X ray results and charge transfer are considered.