Interlayer potentials for fcc (1 1 1) planes of Pd–Ag random alloys

Using ab initio alloy theory in combination with the Chen-Mِbius inversion method, we obtain the interaction potentials between layers of the face centered cubic (fcc) (1 1 1) plane family for elemental Pd and Ag metals and for Pd0.5Ag0.5 random alloy. Based on the interlayer potentials, we investigate properties related to the fcc (1 1 1) planes, such as the stacking fault energy, shear elastic constant, surface energy, surface relaxations, and phonon dispersion along the fcc [1 1 1] direction. The results agree well with those obtained by fully self-consistent ab initio calculations and also with the available experimental data, indicating that the properties related to the close-packed planes are well described by the interlayer potentials.