On-the-fly clustering for exascale molecular dynamics simulations.

In extreme conditions, we aim to understand how the physical properties of matter are altered under shock conditions. This includes examining the equation of state, which relates pressure to density, as well as the mechanisms of phase transitions, such as solid to solid, solid to liquid, or solid to plasma. We also investigate how shocks can induce damage and affect the constitutive behavior of solid materials.

Extreme conditions are characterized by very high pressure applied over a very short time scale or at a very high loading rate. To achieve this, we utilize various loading devices. For instance, a diamond anvil cell can generate super high pressures, reaching hundreds of gigapascals, but at relatively low loading rates. For higher loading rates, we employ a gas gun, which propels a bullet that impacts a target, generating a shock wave.

Additionally, we use lasers that focus energy onto a metal surface, creating a plasma that ejects material and generates shock waves in the sample. A shock wave is defined as a compressive pressure wave that propagates through the material.