Note 10.

Five-fold rotational symmetry causes a srtict repetitive (translational) structure to be impossible. The only rotations (i.e. rotational symmetries) that are compatible with a translative (periodic, repetitive) pattern are 1-fold (360 degrees rotation), 2-fold (180 degrees rotation), 3-fold (120 degrees rotation), 4-fold (90 degrees rotation) and 6-fold (60 degrees rotation) .

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