  We use Brownian Dynamics simulations in combination with the umbrella
sampling technique to study the effect of shear flow on homogeneous crystal
nucleation. We find that a homogeneous shear rate leads to a significant
suppression of the crystal nucleation rate and to an increase of the size of
the critical nucleus. A simple, phenomenological extension of classical
nucleation theory accounts for these observations. The orientation of the
crystal nucleus is tilted with respect to the shear direction.
