  We present a method that systematically simplifies isotropic interactions
designed for targeted self-assembly. The uncertainty principle is used to show
that an optimal simplification is achieved by a combination of heat kernel
smoothing and Gaussian screening. We use this method to design isotropic
interactions for self-assembly of complex lattices and of materials with
functional properties. The interactions we derive are significantly simpler
than those previously published, and it is realistic to discuss explicit
experimental implementation of the designed self-assembling components.
