  A dislocation moving through a quasicrystal is leaving in its wake a fault
denoted phason wall. For a two-dimensional model quasicrystal the disregistry
energy of this phason wall is studied to determine possible Burgers vectors of
the quasicrystalline structure. Contrary to periodic crystals, the disregistry
energy is an average quantity with large fluctuations on the atomic scale.
Therefore the dislocation core structure and mobility cannot be linked to this
quantity e.g. by a Peierls-Nabarro model. Atomistic simulations show that
dislocation motion is controlled by local obstacles inherent to the atomic
structure of the quasicrystal.
