The cubic structure of Ag 3 AuSe 2 was maintained across all Ag 3 Au(Se,Te) 2 samples. A uniform leftward shift of the (312) peak, marked by the grey dashed line in Figure , indicates consistent cell volume expansion, while maintaining the cubic crystal structure. This expansion was further confirmed by the linear increase in lattice parameter as a function of Te fraction, shown in Figure . The nominal stoichiometry of the Ag 3 Au(Se,Te) 2 ingots was verified by EDS elemental analysis. Results are summarized in Figure . Corresponding elemental maps projecting the fractured ingot surfaces are presented in Figure . The elements, Ag, Au, Se and Te were uniformly distributed across the scanned area, except at x = 0.9, due to impurities. In this sample, gold-deficient regions in the EDS map suggest the presence of Ag 2 Te patches with some Te sites likely replaced by Se. These impurities are consistent with the PXRD results.