Reported herein are the synthesis and structures of two high-nuclearity AuAg nanoclusters, namely, [Au78Ag66(C CPh)(48)Cl-8](q-) and [Au74Ag60(C CPh)(40)Br-12](2-). Both clusters possess a three-concentric-shell Au-12@Au-42@Ag-60 structure. However, the dispositions of the metal atoms, and the ligand coordination modes, of the outermost shells of these clusters are distinctly different. These structural differences reflect the bonding characteristics of the halide ligands. As revealed by density functional theory analysis, these clusters exhibit superatomic electron shell closings at magic numbers of 92 (for q = 4) and 84, respectively, consistent with their spherical shapes. Both clusters exhibit unusual multivalent redox properties.