Density-functional theory and computational chemistry

Computational (or \"quantum\") chemistry is a field of science that simulates chemistry on computers. Computational chemists can predict the structures, properties, and spectra of small and large molecules, and the directions and energetics of chemical reactions, using quantum theory and quantum-theory-based computer software. The quantum theory of the motions of electrons in molecules is very complicated, but an elegant approach called \"density-functional theory\" (DFT) has had enormous recent impact in simplifying and reducing the cost of chemical computations. DFT underlies most applications in computational chemistry today. Our own work over the past 25 years is largely responsible for this DFT revolution in quantum chemistry.

Fundamental and practical problems remain, however, in the application of DFT to weak (or \"van der Waals\") intermolecular interactions that govern biological, condensed-matter, and nanochemical systems. In 2005 we began developing a novel theory of van der Waals interactions which is now essentially complete. In the next few years we will implement this theory in new computer software of wide availability. The application of rigorous density-functional theory to biological, condensed-matter, and nanochemical problems will, for the first time, be possible by virtually all chemists.

Other fundamental remaining problems in DFT will also be addressed. These include: \"nonlocality\" effects in molecules, \"strong\" interelectronic correlations in molecules, and relativistic effects (which have significant impact on the chemistry of heavy elements).