First-principles calculation of stacking-fault energies in substitutionally disordered alloys

A generalization of the coherent-potential approximation to two-dimensional defects in substitutionally disordered alloys, based on the layer Korringa-Kohn-Rostoker method, is presented. We illustrate the method with ab initio, self-consistent total-energy calculations implemented within the muffin-tin approximation of intrinsic stacking-fault energies in various ${\mathrm{Cu}}_{1\mathrm{-}\mathit{x}}$ ${\mathrm{Zn}}_{\mathit{x}}$ alloys (x=0,0.1,0.2, and 0.3). Excellent agreement is found between calculated fault energies and experimentally determined values.