Rowlands, D. A., Ernst, A., Györffy, B. L., Staunton, J. B.
Density functional theory for disordered alloys with short-range order: Systematic inclusion of charge-correlation effects
Physical Review B 73, (16),pp 165122/1-18 (2006)
For many years, density-functional-based calculations for the total energies of substitutionally disordered alloys have been based upon the Korringa-Kohn-Rostoker coherent-potential approximation (KKR-CPA). However, as a result of the single-site nature of the KKR-CPA, such calculations do not take into account important local environmental effects such as charge correlations (the Madelung energy) and chemical short-range order (SRO). Here the above approach is generalized by combining the recently developed Korringa-Kohn-Rostoker nonlocal coherent-potential approximation with density functionl theory, showing how these effects may be systematically taken into account. As a first application of the theory, total energy calculations for the bcc CU50Zn50 solid solution are presented, showing how the total energy varies as a function of SRO. The fcc Cu60Pd40 and Cu77Ni23 systems are also investigated.
TH-2006-20