  The deformation behaviour of the intermetallic Al$_{2}$Cu-phase was
investigated using atomistic simulations and micropillar compression, where
slip on the unexpected {211} and {022} slip planes was revealed. Additionally,
all possible slip systems for the intermetallic phases were further evaluated
and a preference for the activation of slip systems based on their effective
interplanar distances as well as the effective Burgers vector is proposed. The
effective interplanar distance corresponds to the manually determined
interplanar distance, whereas the effective Burgers vector takes a potential
dislocation dissociation into account. This new order is: {211}1/2<111>,
{022}1/2<111> and {022}<100>, {110}<001>, {310}<001>, {022}<011>,
{110}1/2<111>, {112}<110> and {112}1/2<111> from high to low ratio of
deff/beff. Also, data on the critical resolved shear stresses of several of
these slip systems were measured.
