Intermolecular Interactions and Computational Modeling

Intermolecular interactions are important in many branches of science. Intermolecular forces are the molecular interactions that exist between molecules. This chapter focuses on the analysis of intermolecular interactions in crystalline solids in general and pharmaceutical molecules in particular. It emphasizes the nature of each intermolecular interaction. The chapter discusses the various forms of intermolecular interactions in organic crystals and their implications on the molecular packing as well as on the physicochemical properties of pharmaceutical organic compounds. It presents the examples that show how experimental and computational methods are routinely used for calculating or estimating the strength of these interactions. The chapter covers methodologies in crystal packing prediction, with emphasis on the achieved progress and the current, inherent difficulties in this area. It also presents the concepts and advances in exploring the electronic origin of intermolecular interactions in organic crystals.