Materials at Extremes: Discovery Science with LAMMPS and Exascale Computers

The behavior of materials under extreme conditions pressures and temperatures is of key importance for understanding interiors of exoplanets and harnessing clean inertial fusion energy (IFE). The advent of powerful laser and pulsed-power compressions, and in-situ X-ray synchrotron and free electron laser (XFEL) diffraction experiments provide unique opportunities to recreate and probe the high-PT environment of exoplanetary cores and IFE implosions in the laboratory. However, science return is limited due to difficulty of obtaining atomic-scale insight from these sophisticated and expensive experiments. By developing machine-learning models of interatomic interactions at extreme conditions and employing the most powerful computers in the world to run LAMMPS molecular dynamics (MD) simulations, we are able to simulate atomic-scale dynamics of materials response at experimental time and length scales in quantum accurate, billion atom MD simulations. In this talk I will discuss several transformative LAMMPS MD simulations including synthesis of long-sought BC8 high-pressure post-diamond phase of carbon, inelastic deformations in shocked diamond and complex phase transitions in IFE ablator materials.

• Thursday, 10 Aug 2023
• 15:25 - 15:55 EDT