By contrast, the computed crystal energy landscape for TBAP (Figure ) contains several regions of low-energy, low-density predicted structures that fall well below the bulk energydensity trend. These low energy 'spikes' are reminiscent of those on the landscapes of the triptycene benzimidazolone molecule, T2, and also trimesic acid, both of which corresponded to experimentally accessible porous structures. These spikes correspond to isolated, deep basins on the lattice energy surface, separated by a high energy barrier from regions of the lattice energy surface corresponding to dense structures. The most prominent of these spikes has a density of ca. 0.6 g cm ; the lowest energy structure in this spike, 1 (Figure ) has a lattice energy 57 kJ mol -1 above the dense global minimum on the TBAP landscape. TBAP structure, 1, features 2-dimensional sheets with rhomboid voids held open by acidacid hydrogen bonds between TBAP molecules (Figure ). These sheets are stacked to form infinite pyrene columns (Figure ) and parallel channels that run perpendicular to the hydrogen-bonded sheets. A second spike at a density of ca. 0.75 g cm features similar structures containing one-dimensional channels between π-stacked pyrene columns, but with some collapsed channels (SI, Figure ). Thus, the CSP results suggested that TBAP had the potential for the construction of porous frameworks, like MOFs but without the inclusion of metals. During the course of this study, although after these calculations, structure 1 was in fact reported independently by another research group, confirming our prediction.