The picture that emerges, across several levels of theory, is one of a slip-stacked AA motif with a small (< 2 Å) lateral offset. On the other hand, it is unclear why XSAPT+MBD significantly destabilizes the ABtype structures, relative to DFT results. Some part of this is likely a basis-set effect, as results for (half-COF1) 2 in Table indicate that the (7 Å, 7 Å) structure is stabilized by 4.5 kcal/mol, relative to the (0, 0) structure, as the basis set is enlarged from def2-ma-SVP to def2-ma-TZVP. An investigation of these discrepancies is ongoing.