Schematic of double shock simulations. The first compression wave is generated by a piston moving with constant velocity. The double shock compression is initiated by increasing piston velocity to a time instant. Three-wave structure due to elastic-inelastic shock wave splitting of the first compression is shown after the second piston velocity applied within time interval.
The goals of this INCITE project are to design compressive pathways towards synthesis of elusive and long-sought post-diamond BC8 phase of carbon; uncover kinetics effects in phase transformations to BC8 phase from diamond and amorphous carbon in explicit, billion atom, double-shock simulations at micrometer and nanosecond time scales.
The main objective of this project is to perform transformative quantum-accurate, billion atom molecular dynamics (MD) simulations on exascale DOE computers Frontier and Aurora to uncover the fundamental physics of carbon at extreme pressures and temperatures. The discovery science enabled by exascale computing is uniquely coupled to several experimental projects, led by the PI and his experimental collaborators, aimed at observing the phenomena, predicted by the team’s simulations. The team’s scientific goals are to design compressive pathways towards synthesis of elusive and long-sought post-diamond BC8 phase of carbon; uncover kinetics effects in phase transformations to BC8 phase from diamond and amorphous carbon in explicit, billion atom, double-shock simulations at micrometer and nanosecond time scales. They also seek to uncover fundamental mechanisms of inelastic deformations in shock compressed diamond and determine the origin of anomalous persistence of crystalline anisotropy at extreme compressions of diamond up to its melting line in multi-billion-atom simulations of split-shock wave propagation. Finally, they are working to investigate fundamental physics of shock melting and refreezing and determine the effect of refreeze microstructure on modulating initially planar second shock in multi-billion atom single and double shock simulations.
