Computational prediction of volatile host minerals in planetary interiors

Abstract

Volatile elements like potassium and nitrogen have important implications for the habitability and interior structures of planets. However, how they are stored in silicate at high pressure is largely unknown. In this thesis, I explore volatile host minerals in extreme pressure and temperature conditions found in planetary interiors, using random structure searching and density functional theory. I investigate the K2O-SiO2-Al2O3 ternary and the H-Si-N-O quaternary systems and identify stable compounds that contain potassium in deep Earth, and nitrogen in both Earth and ice giants. I have predicted 11 potassium-silicates and aluminates, and seven nitrogen-rich compounds that are stable in deep Earth. Further, the study extends to ice-rock mixtures in ice giants, exploring the role of H-Si-N-O compounds in the formation of gradual transition zones in ice giants. This research contributes to our understanding of volatile host minerals under extreme conditions, providing insights into hidden reservoirs of volatile elements in deep Earth, and the geochemistry of ice-rock mixtures in ice giants.