9 A quasicrystal

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"laue" can also arrange atoms in a quasicrystalline array. Here is a displacement type quasicrystal with identical atoms arranged on lattice sites generated from a Fibonacci series with the two interatomic spacings in the ratio of 1.27. You will find striking variations in the qualitative appearance of the pattern as this ratio is changed. Try 1.5 for example, or 2.0, or 1.95..

The quasicrystal is another arrangement which does not have a periodicity according to the usual definitions. The diffraction pattern is qualitatively different again from those we have seen up to now. The unbroadened diffraction peaks are arranged in an apparently orderly fashion, but by zooming in you see that there is apparently an infinite hierarchy of them.