From Atomistic Insights to Planetary Interiors: Simulating Materials Under Extreme Conditions

Planetary interiors compress materials to millions of atmospheres, creating exotic states of matter that remain poorly understood under the extreme temperatures.  My research uses quantum molecular dynamics (QMD) to explore how exotic oxides and metals behave under such extreme conditions. Earth’s mantle has high oxygen fugacity, which may allow formation of exotic superoxides including MgO₂. Our QMD and phonon analyses at finite temperatures show that its tetragonal phase remains stable while the cubic phase does not. These findings along with ongoing conductivity calculations suggest that superoxides could play an important role in heat and oxygen transport within terrestrial and exoplanetary interiors. I further explored the FCC-phase of nickel, a major constituent of Mars’s core, by developing a machine-learned force field trained on accurate quantum-mechanical energies to accelerate large-scale QMD simulations across 20 to 40 GPa. The model resolves inconsistencies previous theoretical and experimental data in melting behavior and reveals directional sound-speed anisotropy in solid nickel that may contribute to seismic anisotropy in Mars’s core. Together, these studies bridge first-principles based atomistic insights and planetary dynamics, highlighting the exotic behavior of matter at extreme conditions.