Intermolecular Interactions of Large Systems: Boron Nitrides, Acenes, and Coronenes.

In a recent contribution [Fishman et al., J. Chem. Theory Comput. 2025, 21, 2311-2324], we introduced another approach to benchmarking noncovalent interactions by not benchmarking interaction energies of different dimers but by considering the evolution of interaction energies with increasing system size. Here, we extend the benchmark set to more species, such as electrostatically bound borazine dimers as well as the minimum-energy structures of parallel displaced acene and coronene dimers. While the minimum structures of the parallel displaced acene dimers yield similar results to previously published sandwich-structured acenes, the borazine dimers behave vastly differently, yielding a yet more complete picture of noncovalent interactions and their scalability. In contrast, the polycyclic aromatic hydrocarbon structures─coronenes sandwich-stacked and coronenes parallel displaced─give results consistent with those obtained for both types of the polyacene series, resulting in an updated estimate for the coronene dimer energy. By doing so, we are able to break down various approximations made by state-of-the-art coupled-cluster methods.