Predictions of new crystalline states for assemblies of nanoparticles: Perovskite analogues and 3-D arrays of self-assembled nanowires

A genetic search algorithm for optimizing the packing density of self-assembled multicomponent crystals of nanoparticles predicts several new structures with stoichiometries of AB (fused spheres), ABC(2), ABC(3), ABC(4) and AB(2)C(2). These new structures have hierarchical layered or linear arrangements that could be useful for functional self-assembled systems. For example, the fused-sphere binary crystal assembles with zigzag rows of parallel nanowires. The genetic search suceeds while a comparable stochastic algorithm fails to find any structures better than the well-known unary or binary phase-separated systems.