Tuning Intermolecular Interactions with Nanostructured Environments

It is known that interactions between molecules may change in the presence of nanostructures. However, the exact mechanisms that dictate the tuning of intermolecular interactions remain largely unexplored in computational studies. Here, we employ density-functional calculations with the recently developed many-body dispersion (MBD) method to investigate intermolecular three-body interaction energies (where bodies can be molecules or nanostructures) in a set of nanocomposites. We analyze three representative complexes that display distinct behavior in their interaction profiles, and unravel the physical reasons behind the observed differences. We demonstrate that many-body van der Waals (vdW) interactions can be repulsive, attractive, or neutral with respect to a pairwise treatment of vdW dispersion interactions. Our results indicate that vdW interactions in a given complex can be tuned by suitably choosing its environment. Such tuning may lead to either stabilization or destabilization of the complex, establishing many-body interactions as a useful mechanism for designing novel nanomaterials with desired properties.