  Collisions of light and heavy nuclei in relativistic heavy-ion collisions
have been shown to be sensitive to nuclear structure. With a proposed
$^{16}\mathrm{O}^{16}\mathrm{O}$ run at the LHC and RHIC we study the potential
for finding $\alpha$ clustering in $^{16}$O. Here we use the state-of-the-art
iEBE-VISHNU package with $^{16}$O nucleonic configurations from {\rm ab initio}
nuclear lattice simulations. This setup was tuned using a Bayesian analysis on
pPb and PbPb systems. We find that the $^{16}\mathrm{O}^{16}\mathrm{O}$ system
always begins far from equilibrium and that at LHC and RHIC it approaches the
regime of hydrodynamic applicability only at very late times. Finally, by
taking ratios of flow harmonics we are able to find measurable differences
between $\alpha$-clustering, nucleonic, and subnucleonic degrees of freedom in
the initial state.
