Visualizing the locality of intermolecular interactions in organic crystals.

Density functional theory (DFT) provides a rigorous theoretical framework for analyzing and interpreting electronic structures of molecules and crystals. One electron density-based concept is the Fukui function, which describes the responding sensitivity of a molecular system to electronic perturbations. As a local property, the Fukui function is directly associated with local polarizability, so it may be capable of describing the intermolecular interaction in an organic crystal with regard to molecular packing. Herein, we demonstrate such an application to the aspirin single crystal and discuss potentials of the DFT-based concepts for studying electronic structures of organic crystals.