Characterization of Void space, Large-Scale Structure, and Transport Properties of Maximally Random Jammed Packings of Superballs

The study of dense packings of nonspherical particles enables one to ascertain how rotational degrees of freedom affect packing behavior. We generate dense, maximally random jammed packings of convex superballs, a family of deformations of the sphere, whose degree of deformation is characterized by the deformation parameter p and interpolate between cuboidal and octahedral shapes via the sphere. Here, we characterize their large-scale structure by examining the small wavenumber behavior of their structure factors and spectral densities, and find these packings are effectively hyperuniform. We also compute their distribution of pore sizes, which tend to become smaller as the particles become more aspherical. We also estimate how their transport properties vary as a function of shape. Each of the structural characteristics computed here exhibits an extremum at the sphere point and varies nonanalytically as the particles become aspherical. We find the nonanalytic behavior in the packing fraction on either side of the sphere point is nearly linear, and determine that the rattler fraction decreases rapidly as the particles become aspherical.