Capping Ligands as “Atomic Orbitals” in Superlattice Self-Assembly*

Materials consisting of periodic arrangements of nanocrystals, or nanoparticle superlattices, have unique properties not found in materials whose base units are atoms or molecules. In this talk, we present computational analysis of the interaction of two hydrocarbon-capped nanoparticles including cases of different core sizes, shapes, lengths and the asymmetric case, where the two particles in the pair are not identical. Binding free energies are computed using the Weighted Histogram Analysis Method and we show that these energies display a preference for symmetric pairs. A detailed analysis of ligand shell deformation shows planar interactions between the shells, which is used to explain the preference for symmetric pairs. This analysis also reveals the existence of vortex textures as predicted by the recently proposed Orbifold Topological Model.