Structure and motifs of iron oxides from 1 to 3 TPa

Iron oxides are fundamental components of planet-forming materials. Understanding the Fe-O system's behavior and properties under high pressure can help us identify many new phases states possible in exoplanetary interiors, especially terrestrial ones. Using adaptive genetic algorithm (AGA), we investigate structure iron for a wide range stoichiometries ($0.25\leq x_O \leq 0.8$) at 1, 2, 3 TPa. Five unreported ground-state structures with Fe$_2$O, FeO, Fe$_3$O$_5$, FeO$_2$, FeO$_4$ compositions identified. The calculated density (DOS) suggests that, except FeO$_4$, all metallic, but their carrier densities decrease increasing oxygen content. cluster alignment analysis stable metastable shows that several motifs may co-exist low O In contrast, most content adopt simple BCC motif TPa pressures. Our results provide crystal database modeling understanding interiors exoplanets.