The total energy of ordered and disordered phases of AlAs-GaAs systems is expanded in a series of multiatom interaction energies determined from first-principles linear muffin-tin orbital and linear augmented-plane-wave calculations of simple superstructures. These interaction energies are used to discuss the stability of different superlattices and that of the random alloy.
 

Physical Review B, 40 1642-6, 1989.