Determining 3D atomic positions in a glass-forming alloy (Adapted from ref. [60]. Copyright©2021, Springer Nature). (A) (top left) Representative experimental projection image, where some crystalline features are visible. Scale bar: 2 nm. (top right) Average 2D power spectrum of 55 experimental images, showing the amorphous halo. (bottom) Two 2.4-Å-thick slices of the 3D reconstruction in the x-y (left) and y-z (right) plane, where the majority of type-3 atoms (bright dots) are distributed in the second coordination shell. (B) Experimental 3D atomic model of the glass-forming nanoparticle. (C) (top) Large-field-of-view image of amorphous CuTa film. Scale bar: 30 nm. (bottom left) Magnified image of the region in the corresponding white square. Scale bar: 2 nm. (bottom right) Average 2D power spectrum of all the experimental images. (D) 3D atomic model of a portion of the CuTa thin film with a total of 1808 Cu (gold) and 12,774 Ta (blue) atoms.