Comparison of Si, O, C, P, Mg, H, and N contents of the Earth’s core derived using different methods. Red diamonds [this work (A)] show an estimate of the core composition using *C*^{C} = *C*^{E}/[*f* + (1 − *f*)/*D*], where *C*^{C} represents core composition, *C*^{E} is bulk Earth composition (), *f* is mass fraction of metallic core, and *D* is partition coefficients from . Blue triangles [this work (B)] show the core composition derived using the definition of partition coefficient, the *C*^{C} = *D* × *C*^{M}, where *C*^{M} is the primitive mantle composition (bulk silicate Earth) of ref. . Green circles [this work (C)] show the use of the most recent estimates of C, H, and N of the Earth’s mantle () and our *ab-initio* partition coefficients to calculate the corresponding core composition using *C*^{C} = *D* × *C*^{M}. Purple squares are the core compositions given by McDonough () based on volatility curve, cosmochemical constraints, and mass balance of geochemical reservoirs. With the exception of N, core compositions of light elements agree within an order of magnitude or better between different approaches.

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