Density-Functional Theory Group: Research Projects

Quantum-mechanical simulations

Dr G Csanyi, Dr P D Haynes, Prof M C Payne

Computer simulations are playing an important role as a complement to experiment in modern physics, chemistry, materials science and biology. Quantum mechanics describes the atomistic processes underlying all these areas, and while empirically-based methods may be sufficient in familiar situations, such assumptions cannot be relied upon when pioneering new fields or predicting the properties of new materials. In these cases the quantum-mechanical equations must be solved from first principles using only well-controlled approximations.

Our group is at the forefront of the development and application of revolutionary techniques including linear-scaling methods for density-functional theory and hybrid modelling schemes. The former has already enabled simulations of a few thousand atoms to be performed with unparalleled accuracy on systems ranging from biological macromolecules to nanostructures. The latter allows an accurate quantum simulation to be embedded within a fast empirical scheme dynamically, where the extent of the quantum-mechanical region is determined on the fly. Together these advances promise to bring the power of quantum-mechanical simulations to bear on systems of an unprecented scale.

Our goal for the next five years is to combine them and to use the resulting technology to tackle new classes of problems in biology and materials science that are currently beyond the reach of traditional simulation methods. Notoriously hard problems include defect motion and brittle fracture in solids, enzymatic catalysis and transport through cell membranes. In all of these areas, at least one novel aspect of our techniques is essential in order to embark on an accurate simulation that yields quantitative results and makes reliable predictions.

Sponsors: EPSRC, Leverhulme Trust, Royal Society