Charge transfer and ordering energy in a model binary alloy

Intra- and inter-atomic Coulomb interactions have been accounted for in the band theory of the order-disorder transition in binary alloys. The variation of the energy levels of the two kinds of atoms on the two sublattices is determined self-consistently using an extension of the coherent potential approximation (CPA). As an application, the authors investigate the role of the charge transfer in the order-disorder transition of CsCl type structure transitional alloys such as VMn, TiFe and ScCo.