Exemplary selection from the total ensemble of porous BA (top row), BAM1 (moddle row), and BAM2 (bottom row) aggregates for the effective grain radii a_eff = 200 nm (left column), a_eff = 350 nm (middle column), and a_eff = 500 nm (right column) with the corresponding numbers of monomers N_mon and neighbourhood connections N_con. Monomers are sampled to guarantee an exact effective radius a_eff. The radius a_out is associated to the smallest sphere enclosing the entire aggregate. Axes ${\widehat{a}}_1,{\widehat{a}}_2,$ and ${\widehat{a}}_3$ are defined by the grain’s moments of inertia I_a1 > I_a2 > I_a3, where ${\widehat{a}}_1$ is the designated axis of grain rotation.