First Principles Based Multiscale Atomistic Methods for Non-Equilibrium Transport Across Interfaces*

This symposium is focused on Non-equilibrium transport and mixing across interfaces, with papers describing non-equilibrium coupling of transport at interfaces, including mesoscopic and macroscopic dynamics in fluids, plasmas, and other materials over scales from microns to celestial. Most such descriptions deal with the materials in terms of density and equations of state rather than specific atomistic structures and chemical processes. At interfacial boundaries, such atomistic information can be quite relevant, but it is not yet practical to couple phenomena at celestial scales with the atomistic descriptions of chemistry. The starting point for including such information is quantum mechanics (QM). But practical QM calculations are limited to 100’s of atoms for 10’s of picoseconds, far from the scales required to properly inform the continuum level about the atomistics. To bridge this enormous gap, we are developing practical methods to extend the scale of the atomistic simulation by several orders of magnitude while retaining QM accuracy for describing chemical processes. These developments are aimed toward including the relevant chemistry for systems with millions of atoms. We will describe the progress in accomplishing these extensions of first-principles-based atomistic simulations to larger scales while dramatically decreasing computational efforts.