Elemental abundances of Al, Ca, Fe, Ni, and Si, expressed in atomic percent and normalized to Mg and CI chondrites. Squares indicate mantle compositions and circles indicate core compositions, respectively. Blue and red symbols correspond to geochemically inferred present-day compositions Earth and Mars (including the Bulk Silicate Earth, Earth's core, the Bulk Silicate Mars, and the Martian core), which serve as observational reference values. In contrast, the meteoritic end-members (EF, EC, and OC) represent the initial compositional reservoirs adopted in the model. As Mg is used as the normalization reference, its abundance is not shown explicitly.