Retention of noble gases in the deep Earth: Kinetic trapping or stable bonding?

The bonding potential of noble gases in high-pressure silica-bearing solids and melts remains debated, yet it is a central question for understanding their retention behavior and evaluating the role of silicate-bearing phases in the transport and storage of noble gases originally present in the atmosphere. Here, we assess the chemical behavior of noble gases in three silicates: quartz, seifertite, and perovskite. Using the electron localization function and Bader charge analysis, we find no evidence of stable covalent or ionicbonding. The very slow intracrystalline diffusion of heavy noble gases governs their trapping in silicates during crystal growth. Noble gases are more likely to reside in melts or grain boundaries than in silicate crystal lattices.