Accelerating Hybrid Density Functional Theory Molecular Dynamics

For many systems, accurate First-Principles Molecular Dynamics (FPMD) simulations require the use of hybrid density functional theory. Molecular Dynamics requires short wall clock times and thus highly scalable parallel algorithms. The Qbox[1] code implements the recursive subspace bisection algorithm[2,3] which accelerates hybrid density functional theory calculations by creating a set of localized orbitals to reduce the number of exchange integrals computed. This approach allows for controlled accuracy and requires no a priori assumptions about localization. We discuss heuristic algorithms for improving the scalability and performance of this approach. We then demonstrate these improvements in applications to aqueous solutions and water-metal interfaces. \\{} [1] http://eslab.ucdavis.edu/software/qbox \\{} [2] F.~Gygi, Phys.~Rev.~Lett.~{\bf 102}, 166406 (2009).\\{} [3] F.~Gygi and I.~Duchemin, J.~Chem.~Theory Comput.~{\bf 9}, 582 (2012).