Intermolecular Chemistry from Density-Functional Theory

Theoretical chemistry complements experiment by allowing researchers to model chemical processes computationally. Theory can interpret and explain experimental findings, and is poised to guide experimental design of new drugs, catalysts, and materials, reducing required laboratory time and resources. Density-functional theory (DFT) is the workhorse of computational chemistry, being the most widely used modeling technique for applications ranging from biochemistry to materials physics. However, while accurate application of DFT to covalent bonding and intramolecular chemistry was primarily a challenge for the 20th century, its application to non-covalent interactions and intermolecular chemistry remains a challenge for the 21st. London dispersion, while being the weakest intermolecular interaction, is ubiquitous in chemistry. Accurate modeling of dispersion is essential in controlling the 3D structure of biomolecules, solute-solvent interactions, friction and adhesion, molecular self assembly, surface adsorption, molecular crystal packings, and phase transitions. Within the realm of materials chemistry, accurate theoretical description of intermolecular interactions is particularly relevant for computational design and screening of functional materials and interfaces with targeted properties. The long-term objectives of my research program are to develop a comprehensive set of tools to allow routine theoretical treatment of intermolecular chemistry, with simultaneous high accuracy and computational efficiency, and to use these tools to tackle outstanding challenges in the field of materials chemistry. To address these objectives, the present proposal focuses on three central research themes: (i) fundamental research on London dispersion, improving the accuracy and efficiency of DFT-based dispersion methods (ii) development of hierarchical techniques for molecular crystal-structure prediction; and (iii) large-scale computational modeling of 2D materials and interfaces. Impacts of the work within the field will be the advancement of our fundamental understanding of London dispersion, electronic interactions, and density-functional theory. The new methods and implementations to be developed should become widely used within the computational chemistry community, both within Canada and worldwide, for applications including modeling of biomolecular systems, organic chemistry, catalysis, materials chemistry, and solid-state physics. This will serve to further strengthen Canada's long-held position as an international leader in the field of density-functional theory. These methods can also be used to facilitate rapid, high-throughput screening of candidate materials, streamlining the design of functional materials for clean-energy and technology applications, and leading to devices that will eventually improve the standard of living for Canadians.