Reference dissociation curves of SCS-CC2/CBS(3,4) quality were taken here from ref. 12 as we previously established this method's reasonable comparison with higher level coupled cluster results for the benzene excimer. We refer to our previous paper for a detailed analysis of SCS-CC2 in comparison to coupled cluster singles doubles with perturbative triples excitation correction [CCSDR(3)] across varied basis set size and extrapolated to the CBS limit. All single-point, linear-response TD-DFT calculations within the adiabatic approximation were performed with ORCA 5.0.3 with the def2-TZVP AO basis set and large quadrature-grid option 'DEFGRID2'. The resolution of the identity (RI) approximation was applied with appropriate auxiliary basis functions. The frozen core approximation was also used, which preliminary calculations on our largest system suggest does not have significant impact on the resultant interaction energies even for our largest system or methods with large MP2 components. SCF steps were performed with a convergence threshold of 10 -7 E h . The symmetry detection threshold was lowered from the default to 3 × 10 -4 , due to non-linear monomer structures (discussed in ref. . For each point along the dissociation curve fifteen excited states were calculated to minimise state mixing and ensure the correct state was chosen for each point.