A complicated quasicrystal approximant ε16 predicted by the strong-reflections approach

• The structure of a complicated quasicrystal approximant ϵ16 was predicted from a known and related quasicrystal approximant ϵ6 by the strong-reflections approach. Electron-diffraction studies show that in reciprocal space, the positions of the strongest reflections and their intensity distributions are similar for both approximants. By applying the strong-reflections approach, the structure factors of ϵ16 were deduced from those of the known ϵ6 structure. Owing to the different space groups of the two structures, a shift of the phase origin had to be applied in order to obtain the phases of ϵ16. An electron-density map of ϵ16 was calculated by inverse Fourier transformation of the structure factors of the 256 strongest reflections. Similar to that of ϵ6, the predicted structure of ϵ16 contains eight layers in each unit cell, stacked along the b axis. Along the b axis, ϵ16 is built by banana-shaped tiles and pentagonal tiles; this structure is confirmed by high-resolution transmission electron microscopy (HRTEM). The simulated precession electron-diffraction (PED) patterns from the structure model are in good agreement with the experimental ones. ϵ16 with 153 unique atoms in the unit cell is the most complicated approximant structure ever solved or predicted.

Subject headings

NATURVETENSKAP  -- Kemi -- Oorganisk kemi (hsv//swe)

NATURAL SCIENCES  -- Chemical Sciences -- Inorganic Chemistry (hsv//eng)

Keyword

Inorganic chemistry

Oorganisk kemi

Publication and Content Type

ref (subject category)

art (subject category)