Chirality measures for nanostructures

We survey the different definitions of chirality and the methods that have been devised to compute chirality metrics, with emphasis on the methods that became prevalent in chemistry and materials science, the Hausdorff Chirality Measure (HCM) and the Osipov-Pickup-Dunmur (OPD) index. We also discuss the recently introduced Graph Theoretical Chirality (GTC) index, which is expected to become an alternative to the OPD index. We demonstrate how these different approaches can be applied to systems ranging from a few nanometers to micrometers and above, as long as structural information is available from either computer simulations or experimental data. These recent breakthroughs in the calculation of chirality metrics should pave the way to deepen our understanding of how primary chiral information is translated into secondary chiral properties and how these lead to applications, providing the basis for a theory of chiral nanomaterials.