‘Cluster–disordered glue’ model for icosahedral quasicrystals

A model for icosahedral quasicrystals is proposed, in which clusters become nearly perfect in the sense of having fivefold symmetry and the atoms in the glue region tend to become disordered. There is only a subtle rearrangement of atoms between the quasicrystalline phase and the related – existing or possible – crystalline phase. This model is consistent not only with diffraction data, but also with the results of positron annihilation and other non-diffraction experiments.