Abstract
The core of the Earth consists mainly of iron and nickel, forming an iron-nickel alloy. At the same time, sulfur is one of the potential candidates for the role of a light element in the inner core. To date, many theoretical studies have been conducted by quantum chemical modeling to search for intermediate compositions and structures in systems such as Fe-C, Fe-H, Fe-O, Fe-Si, Fe-S and Fe-P up to pressures of 400 GPa. Despite extensive research on the iron-light element systems, to date no mineralogical model of the Earth's core has been created that fully corresponds to the observed seismological data. A possible reason for this discrepancy may be insufficient consideration of the influence of the core's key alloying element, nickel. Theoretical studies for the nickel-light element system at high pressures have not been sufficiently carried out. Therefore, it is necessary to conduct more in-depth studies of these binary systems in order to further study and identify possible intermediates in triple Fe-Ni-S systems.