Five-fold symmetry in Au–Si metallic glass

Herein, Au8Si dodecahedrons with local five-fold symmetry are revealed as building blocks in Au–Si metallic glass, and the interconnection modes of Au8Si dodecahedrons determine the medium-range order. With dimensionality reduction, the surface ordering is attributed to the motif transformation of Au8Si dodecahedrons into planar Au5Si pyramids with five-fold symmetry, and thus the self-assembly of Au5Si pyramids leads to the formation of the ordered Au2Si monolayer with the lowest energy.