Related papers: Noble-Gas Solubility in Solid and Fluid Metallic H…
Hydrogen in its metallic form is the most common material in our solar system, found under the extreme pressure and temperature conditions found in giant planets. Such conditions are inaccessible to experiment and consequently, theoretical…
The formation of the giant planets in our solar system, and likely a majority of giant exoplanets, is commonly explained by the accretion of nebular hydrogen and helium onto a large core of terrestrial-like composition. The fate of this…
Although they are rare elements in the Earth's mantle, noble gases (NG) owe to their strongly varying masses contrasting physical behaviors making them important geochemical tracers. When partial melting occurs at depth, the partitioning of…
The mixing behavior of hydrogen with heavier elements plays a key role in modeling the interiors of giant planets such as Jupiter and Saturn. Using density functional theory combined with molecular dynamics, we investigate hydrogen-neon…
We use a novel technique to solvate silver cations in small clusters of noble gases. The technique involves formation of large, superfluid helium nanodroplets that are subsequently electron ionized, mass-selected by deflection in an…
Implantation and subsequent behaviour of heavy noble gases (Ar, Kr, Xe) in few-layer graphene sheets and in nanodiamonds is studied both using computational methods and experimentally using X-ray absorption spectroscopy. X-ray absorption…
The test particle method has been used in conjunction with molecular dynamics simulations to evaluate the solubility of noble gases in silicate melts of various compositions. At low pressure the calculated solubility constants (the inverse…
Ab initio random structure searching with density functional theory was used to determine the zero-temperature structures of atomic metallic hydrogen from 500 GPa to 5 TPa. Including zero point motion in the harmonic approximation, we…
The polymorphism and mechanism of helium compounds is crucial for understanding the physical and chemical nature of He-bearing materials under pressures. Here, we predict two new types of He-bearing compounds, MgHe and MgnHe (n = 6, 8, 10,…
Helium and rare gases (RG: Ne, Ar, Kr, Xe) are typically considered chemically inert, yet under the extreme pressures of planetary interiors they may form compounds with unexpected properties. Using crystal structure prediction and…
The noble elements constitute the simplest group in the periodic table. At low temperatures or high pressures, the liquid phase solidifies into a face-centered cubic crystal structure (except helium). In the companion paper, we investigated…
Noble gases are accreted to the giant planets as part of the gas component of the planet-forming disk. While heavier noble gases can separate from the evolution of the hydrogen-rich gas, helium is thought to remain at the protosolar H/He…
Many sub-Neptune exoplanets have been believed to be composed of a thick hydrogen-dominated atmosphere and a high-temperature heavier-element-dominant core. From an assumption that there is no chemical reaction between hydrogen and…
Nitrogen oxides are textbook class of molecular compounds, with extensive industrial applications. Nitrogen and oxygen are also among the most abundant elements in the universe. We explore the N-O system at 0 K and up to 500 GPa though ab…
Helium (He) is the most inert noble gas at ambient conditions. It adopts a hexagonal close packed structure (P63/mmc) and remains in the insulating phase up to 32 TPa. In contrast, lithium (Li) is one of the most reactive metals at zero…
The equation of state of liquid metallic hydrogen is solved numerically. Investigations are carried out at temperatures, which correspond both to the experimental conditions under which metallic hydrogen is produced on earth and the…
The molecular phase of hydrogen converts to the atomic metallic phase at high pressures estimated usually as 300 - 500 GPa. We analyze the decay of metallic phase as the pressure is relieved below the transition one. The metallic state is…
Gas hydrates are considered fundamental building blocks of giant icy planets like Neptune and similar exoplanets. The existence of these materials in the interiors of giant icy planets, which are subject to high pressures and temperatures,…
The metal-based noble gas compounds exhibit interesting behavior of electronic valence states under pressure. For example, Xe upon compression can gain electrons from the alkali metal, or lose electrons unexpectedly to Fe and Ni, toward…
The evolution of the atmospheric noble gas composition during the past few decades has hardly been studied because, in contrast to many other atmospheric gases, systematic time-series measurements have not been available. Based on…