  In this paper we introduce a new method to design interparticle interactions
to target arbitrary crystal structures via the process of self-assembly. We
show that it is possible to exploit the curvature of the crystal nucleation
free-energy barrier to sample and select optimal interparticle interactions for
self-assembly into a desired structure. We apply this method to find
interactions to target two simple crystal structures: a crystal with simple
cubic symmetry and a two-dimensional plane with square symmetry embedded in a
three-dimensional space. Finally, we discuss the potential and limits of our
method and propose a general model by which a functionally infinite number of
different interaction geometries may be constructed and to which our reverse
self-assembly method could in principle be applied.
