Stacking fault energies of nondilute binary alloys using special quasirandom structures

Generalized stacking fault energies of nondilute binary alloys in the Ag-Au-Pd system are calculated using density functional theory and special quasirandom structures. Supercells containing 90 and 135 atoms are compared for direct calculations of the generalized stacking fault energy, and the axial interaction model is used to estimate the intrinsic stacking fault energy. The axial interaction model approximates the directly calculated energy to within 10% in most cases, but is sensitive to the particular structures used. Increasing the number of atoms used for direct calculations decreases the uncertainty of the calculated stacking fault energies in most cases, and we show that this uncertainty is related to certain correlations between pairs of adjacent layers within the supercell.