(color online) Atomic packing of metallic glasses. (a) and (b) Solute-centered clusters plus FCC or HCP sphere-packing scheme proposed by Miracle.^[15] With permission from Nature Materials. Copyright 2004 Nature Publishing Group. Solute-centered clusters are considered as the sphere-like structure element. Different colors represent solvent or solute atoms with different atomic size. (c) Solute-center polyhedra, such as Icosahedra, as the structure units and connected by sharing vertex (VS), faces (FS), tetrahedra (TS), and edges (ES).^[20] (d) The existence of defects, such as ‘vacancies’ even ‘cavities’ in MGs.^[20] With permission from Physical Review Letters. Copyright 2009 American Physics Society. The illustration of the connectivity degree of the full icosahedra in (e) Cu₄₆Zr₄₇A_l7 MG and (f) Cu₄₆Zr₅₄ MG. (g) Power-law scaling and fractal nature of metallic glasses revealed by the statistics of the relationship between and density of a variety of MGs.^[21] With permission from Nature Materials. Copyright 2009 Nature Publishing Group. (h) The density of a compressible MG, La₆₂Al₁₄Cu Ag Ni₅Co₅, has 2.5 power of Q ₁.^[23] With permission from Physical Review Letters. Copyright 2014 American Physics Society. (I) A dimensionality crossover between fractal short-range and homogeneous long-range structures .^[25] With permission from Science. Copyright 2015 AAAS.