Stable ligands adopted a range of tilt angles (8.55-56.98 • , calculated with respect to the perovskite normal) and exhib-ited both Herringbone (Figure ) and π-π stacked (Figure ) packing motifs. There is a bias towards π-π stacked structures since the construction algorithm used to initialize the simulations treated all ligands as identical. The occurrence of Herringbone structures therefore reflects spontaneous symmetry breaking between the ligands during the MD relaxation. Such alternating patterns allow ligands that are wider than the lattice repeat unit to pack using part of the neighboring unit cell, thereby greatly expanding the space of 2D-perovskite compatible ligands. The Herringbone packing configurations were only seen in OE-mono series, which we hypothesize reflects the kinetic limitations of converting the larger π-π stacked structures (Figure ) on the constrained MD timescales rather than a thermodynamic preference. With respect to design rules, these results suggest a potentially diverse phase space of ligand packing, with polymorphism and more complicated patterns (e.g., mixed ligand phases) being plausible.