Fig. 1: 3D atomic structures of ICNP-1.
a Schematic shows the spatial gap of fivefold twinned structures in 2D (upper) and 3D (lower). b–d Volume rendering of the reconstruction of ICNP-1 (b). Two 3-Å-thick slices of the 3D reconstruction in [110] directions from (b) show the fivefold coordination environment (c, with red frame), and dislocation insertion and grain boundaries slipping coordination environment (d, with blue frame). The red, blue, and purple dots in (c, d) highlight the atom positions in fcc domain, hcp grain boundary, and fivefold structures, respectively. Scale bar: 1 nm. e Volume isosurface rendering of the atoms in one tetrahedral crystalline domain. f Distribution of the BOO parameter in the geometrically perfect icosahedral particle where six fivefold axes go through the Ih center. The BOO parameters uniformly distributed in the surfaces: fcc atoms have a high BOO (red), hcp boundary atoms exhibit a lower BOO (pink), the atoms in fivefold axis and their coordination atoms have a much lower BOO (white and blue). g Distribution of the BOO parameter in ICNP-1; the dashed line separates the C5 and C5′ faces. h Unwrapped surfaces of 20 domains (each tetrahedral domain has been assigned a number) of ICNP-1 with averaged normalized BOO parameters separated from the C5 and C5′ side. i, j 3D atomic structure of ICNP-1 viewed from two distinct angles. Local atomic coordination environments are colored by the legend at the bottom. Scale bar: 1 nm. k, l The schematic of the grain boundary frame in ICNP-1 viewed from two distinct angles with hcp in blue and fcc in yellow. The red and green dots represent the ending atoms in fivefold and sixfold axis, respectively. The blue, yellow, and purple dots are atoms with hcp, fcc, and Dh symmetry, respectively. The balls in the atomic model with yellow, blue, light purple, dark purple, and white color represent the atoms with fcc, hcp, Dh, Ih, and amorphous structures, respectively. The balls in the atomic model with red and green color represent the ending atoms in fivefold and sixfold axis, respectively. Source data are provided as a Source Data file.
