Electronic structure of ordered and disordered Cu alloys: ${\mathrm{Cu}}_3$Pd, ${\mathrm{Cu}}_3$Pt, and ${\mathrm{Cu}}_3$Au

We present a relativistic study of the electronic structures of both ordered and disordered ${\mathrm{Cu}}_3$Pd, ${\mathrm{Cu}}_3$Pt, and ${\mathrm{Cu}}_3$Au alloys. The electronic-structure calculations were performed with use of the fully relativistic Korringa-Kohn-Rostoker (KKR) and KKR–coherent-potential-approximation methods for the ordered and disordered phases, respectively. We focus on the changes in the electronic structure due to disorder and by isoelectronically replacing the 4d element Pd by the 5d element Pt and then its neighbor Au. We also discuss controversies concerning the electronic structure of the disordered ${\mathrm{Cu}}_3$Pd alloy.