A Computational Method to Study Packing on Deformable Shells

Many problems in softmatter and membrane biophysics, such as studying equilibrium configurations of protein clusters on cell-membranes, highly defect ridden structures of Gag polyproteins in immature HIV capsids, and the unusual fluid-like state of Archaeal viruses [1] can all be analyzed as systems of interacting particles (typically representing proteins or protein capsomers) on deformable fluid surfaces. The coupled interactions between the particles and the underlying elastic medium to which they are constrained pose significant computational challenges. Existing methods often employ expensive constraints to anchor particles to the surface or artificially restrict their movement yielding spurious equilibrium states. In this talk, we present a new approach that circumvents existing challenges to obtain reliable equilibria. We apply the method to study the generalized Thomson problem of packing interacting particles on a deformable shell. In this context, we investigate particle symmetries, surface tessellation, and surface shape as the fluid membrane is progressively covered by interacting particles.


[1] Useful scars: Physics of the capsids of archaeal viruses, L.E. Perotti et. al, Phys Rev E 94 (2016).