Emergent complexity from simple anisotropic building blocks: Shells, tubes, and spirals

We describe a remarkably simple, generic, coarse-grained model involving anisotropic interactions, and characterize the global minima for clusters as a function of various parameters. Appropriate choices for the anisotropic interactions can reproduce a wide variety of complex morphologies as global minima, including spheroidal shells, tubular, helical and even head-tail morphologies, elucidating the physical principles that drive the assembly of these mesoscopic structures. Our model captures several experimental observations, such as the existence of competing morphologies, capsid polymorphism, and the effect of scaffolding proteins on capsid assembly.