Unconventional iron-magnesium compounds at terapascal pressures

Being a lithophile element at ambient pressure, magnesium has been long believed to be immiscible with iron. Authors of recent study showed that pressure turns into siderophile and can produce unconventional Fe-Mg compounds [Gao et al., New J. Chem. 43, 17403 (2019)]. Here, we extend the investigation exoplanetary conditions using an adaptive genetic algorithm-based variable-composition structural prediction approach. We identify several phases up 3 TPa 0 K. Our cluster alignment analysis reveals most predicted prefer body-centered cubic packing motif terapascal pressures. In this paper, provide more comprehensive structure database support future investigations high-pressure behavior ternary, quaternary, etc. involving these elements.