  Experimentally resolving atomic-scale structural changes of a deformed glass
remains challenging owing to the disordered nature of glass structure. Here, we
show that the structural anisotropy emerges as a general hallmark for different
types of glasses (metallic glasses, oxide glass, amorphous selenium, and
polymer glass) after thermo-mechanical deformation, and it is highly correlates
with local nonaffine atomic displacements detected by the high-energy X-ray
diffraction technique. By analyzing the anisotropic pair density function, we
unveil the atomic-level mechanism responsible for the plastic flow, which
notably differs between metallic glasses and covalent glasses. The structural
rearrangements in metallic glasses are mediated through cutting and formation
of atomic bonds, which occurs in some localized inelastic regions embedded in
elastic matrix, whereas that of covalent glasses is mediated through the
rotation of atomic bonds or chains without bond length change, which occurs in
a less localized manner.
