As in conventional SAPT, these energy components are defined directly and not by difference (in contrast to supramolecular calculations of E int ), thus there is no basis-set superposition error and no need for counterpoise correction. Components include electrostatics (E elst , defined as Coulomb interactions between isolatedmonomer charge densities), exchange or Pauli repulsion (E exch , arising from the antisymmetry requirement and responsible for steric repulsion), induction (E ind , which contains both polarization and charge-transfer interactions), and dispersion (E disp , for which we use MBD). In contrast to other recent XSAPT+MBD calculations, we do not add the so-called "δHF" correction to E ind . This term accounts for induction effects beyond second order in perturbation theory but requires a supramolecular Hartree-Fock (HF) calculation that is expensive for the larger systems considered here, such as (COF1) 2 , and furthermore we will demonstrate that induction energies are generally small in the systems considered here, and do not have any qualitative effect on the conformational energy landscape. For the XSAPT+MBD calculations, integral screening and shell-pair drop tolerances were both set to τ ints = 10 -14 a.u. and the self-consistent field (SCF) convergence threshold was set to τ SCF = 10 -5 Hartree, except where otherwise noted. The LRC-ωPBE functional is used for all XSAPT+MBD calculations, 37 with a rangeseparation parameter that is tuned for each monomer using the global density-dependent scheme. (This is a facile yet faithful replacement for tuning based on the ionization energy criterion.) Tuning was performed using the def2-TZVP basis set in each case. Two-dimensional surfaces for E int and its components were generated using XSAPT+MBD combined with the def2-TZVPD basis set 50 for (benzene) 2 , def2-ma-TZVP 34 for (annulene) 2 and (porphyrin) 2 , and def2-SVPD for (COF1) 2 . For (COF1) 2 (mesitylene) and some larger COF-1 models that are introduced later, the def2-SVP basis set was used. The two-dimensional XSAPT+MBD scans were generated using a step size ∆x = 0.225 Å = ∆y for (benzene) 2 , 0.5 Å for (annulene) 2 and (porphyrin) 2 , and 0.25 Å for (COF1) 2 (mesitylene). For (COF1) 2 , we performed one scan up to 18 Å displacement using ∆x = 1.0 Å = ∆y and a finer scan up to 3 Å displacement using ∆x = 0.25 Å = ∆y. Previous work has demonstrated that XSAPT+MBD calculations with triple-ζ Karlsruhe basis sets afford convergence errors of ∼ 0.4 kcal/mol for small dimers, although convergence errors are larger when using def2-SVPD (∼ 1.4 kcal/mol) or def2-SVP (∼ 2.7 kcal/mol). For the larger coronene dimer, (C 24 H 12 ) 2 , triple-ζ basis sets again afford sub-kcal/mol convergence errors although results in double-ζ basis sets were ≈ 10 kcal/mol from the basis-set limit. The double-ζ interaction energies are therefore not expected to be quantitative but we will see that a very similar qualitative picture arises as to the origins of offset-stacking. For some of the COF-1 structures, we will report additional single-point calculations using the minimally-augmented def2-ma-SVP basis set.