Hydrogenation of saturated organic and inorganic molecules in metallic hydrogen

Metallic hydrogen is the most common condensed material in the universe, however, experimental studies are extremely challenging, and understanding of this material has been led by theory. Chemistry in this environment has not been probed experimentally, so here we examine carbon, nitrogen, and oxygen in metallic hydrogen using density functional theory calculations. We find that carbon, nitrogen and oxygen react with each other and metallic hydrogen to produce molecules with covalent-type bonding based on sixfold coordinated carbon, threefold oxygen and fourfold nitrogen: CH₆, C₂H₈, C₃H₁₀, OH₃, NH₄, and CH₄OH. In view of the excess hydrogen we refer to them as hypermethane, hyperethane etc. This work suggests that molecular chemistry may take place in very different environments from those found on earth, and may be common throughout the universe. Furthermore, the solubility of C, O, and N casts doubt on whether rocky cores can exist in giant planets.