Many Body Effects in Nanoparticle Superlattices*

Materials consisting of periodic or quasiperiodic arrangements of nanocrystals, instead of atoms or molcelues have unique fundamental properties. In this talk I discuss the binding patterns (equilvalent to atomic orbitals in the binding or atoms or molecules) that enable the organiztion of nanocrystals into periodic structures. I calculate the free energy explicitly and provide a detailed quantification of the many body effects not described by pair interactions. the results are fully consistent with the recently proposed Orbifold Topological Model (OTM).