-Abstract- The crystallographic parameters of atomic and ionic solids are fixed by the size and coordination number of their elemental building blocks, thus restricting the types of structures that can be formed. We have demonstrated that these limitations can be overcome using spherical nucleic acid (SNA) nanoparticle conjugates as “artificial atoms” in superlattice assemblies. These three-dimensional conjugates consist of densely functionalized, highly oriented nucleic acids covalently attached to the surface of inorganic nanoparticles. The strength and length of the programmable DNA “bonds” between these structures can be adjusted by varying DNA sequence and length, and the properties of the “atoms” can be adjusted by varying nanoparticle size, shape, and composition. We have developed design rules for this assembly process, analogous to Pauling’s Rules for ionic solids but ultimately more powerful. These rules can be used as a guide for the rational construction of functional nanoparticle-based materials for plasmonic, photonic, and catalytic applications