Figure 2
From: Previously unknown quasicrystal periodic approximant found in space
The structure of proxidecagonite refined as “Ni44Al136” with pseudo-pentagonal symmetry building blocks (b–d). (a) Down the b-axis across 4 unit cells: the upper left depicts pseudo-pentagonal symmetry subunits (i.e., distorted pentagonal bipyramids and elongated pentagonal bipyramids) arranged in waves with voids filled by trigonal bipyramids, octahedra, and square pyramids, which are drawn in the lower left unit cell in also a wave-like fashion. The lower right shows trigonal bipyramids and pentagonal subunits sharing edges or corners that are isolated in the inset (b–d); the upper right shows all polyhedra tiling the unit cell.
