On the importance of detailed structure in molecular electronics (and why microscopic models cannot see the wood for trees)

We study the charge transport properties of a system of liquid crystal discotic molecules in two distinct phases. To differentiate between the two phases, we use a self-consistent model that describes the pairwise interaction between molecules, the electronic coupling between them and the difference in orbital energies. This multi-scale approach hinges upon having systems that are both accurate (to within atomic resolution) and large (~ 10,000 molecules). The two phases have dramatically different charge transport network topologies, directly correlated to their molecular structures. We quantify the charge transport on both a macroscopic and microscopic scale, taking advantage of the model’s resolution to understand the role of molecular packing in charge transport.