Immiscibility between hydrogen and molten iron in planetary cores

Data from an article in EPSL : "Immiscibility between hydrogen and molten iron in planetary cores" (https://doi.org/10.1016/j.epsl.2026.119851) last updated: v3, 21 April, 2026 Emma R. Stoutenburg 1, Razvan Caracas 2,3, Andrew J. Campbell 31 Department of the Geophysical Sciences, University of Chicago, Chicago, IL 60637, USA2 Institut de Physique du Globe de Paris, Université Paris Cité, Paris 75005, France3 The Research Institute of the University of Bucharest (ICUB), University of Bucharest, Bucharest, Romania Corresponding author: Emma R. Stoutenburg [e-mail] v3: added script that reproduces curves in Fig. 1 of manuscript (S_H_coef.py); corrected equations in the sheet H_X-S_Xfits. This dataset containts ds01_H2_final.xlsx with the following sheets: free-energy: Data derived from the thermodynamic integration and ab initio molecular dynamics simulations, including simulation details (number of iron, nFe; number of hydrogen, nH; the size of the simulation cell, acell_A (in angstroms); volume, vol_ccmol (in cm3/mol H2); pressure, and temperature) as well as the thermodynamic potentials, all in kJ/mol H2 (or kJ/mol H2 K for entropy). H_X-S_Xfits: The fits for Hmix(XH2) and Smix(XH2) at each pressure in the study, 10, 50, and 136 GPa and 3000 K (fit to the functional forms included in the sheet as an image). H_P-S_Pfits: The fits to Hmix(P) and Smix(P) at 3000 K at each XH2. The functional forms fit were Hmix(P) = mP^deg + b and Smix(P) = mP^deg + b; the columns in this sheet are potential (Hmix or Smix), the degree on the pressure, deg, m, and b. dome: We derive the liquid-liquid immiscibility region in the phase diagram using the data from the previous sheets. We find Gmix(P) at 3000 K by fitting Hmix(P) and Smix(P) at 3000 K (H_P-S_Pfits), then we assume these are constant as a function of temperature to find Gmix(P,T) = Hmix – TSmix. We fit this Gmix using the functional forms described above for Hmix and Smix in order to find the common tangents as a function of pressure and temperature, and contruct the immisicibility dome. The columns are : Ferich_XH2 and Hrich_XH2, the H2 mole fraction of the Fe-rich and H-rich immiscibile phases respectively at a given pressure and temperature; Ferich_XH and Hrich_XH are the same, but in terms of the H mole fraction (Fe_1-XH_X); Ferich_wt%H is the weight% of the H in the Fe-rich fluid.