Whereas the intensity decrease is fully explained by the decreasing number of silver atoms within the nanocluster accompanied by a decrease of the superatomic character (σ 0→n ) and collectivity (Γ 0→n ) of the band, the energy variation of the plasmon band as well as its width enlargement remains more complex to rationalize. It was however recently explained by a reduction of the d-contribution in the collective excitations. When finally reaching Au 120 , the silver plasmon band vanishes completely. At this level of theory, we notice the absence of an intense gold plasmon band while pure gold nanoclusters of this size should absorb in the 3.7 to 4.0 eV range. Indeed, in this energy range, the excitations are ruled out by very low values of superatomic character and collectivity indexes (see Figure within Supporting Information).