相关论文: Bond strengthening in dense H2O and implications t…
Water (H$_{2}$O), in all forms, is an important constituent in planetary bodies, controlling habitability and influencing geological activity. Under conditions found in the interior of many planets, as the pressure increases, the H-bonds in…
For most planets in the range of radii from 1 to 4 R$_{\oplus}$, water is a major component of the interior composition. At high pressure H${}_{2}$O can be solid, but for larger planets, like Neptune, the temperature can be too high for…
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,…
Understanding the behavior of the water-ammonia system at high pressure-high temperature conditions is important for modeling the internal dynamics of exoplanet icy mantles. Conventionally, mixtures of ammonia hemihydrate AHH (2:1…
Water and hydrogen at high pressure make up a substantial fraction of the interiors of giant planets. Using ab initio random structure search methods we investigate the ground-state crystal structures of water, hydrogen, and hydrogen-oxygen…
Many extrasolar (bound) terrestrial planets and free-floating (unbound) planets have been discovered. The existence of bound and unbound terrestrial planets with liquid water is an important question, and of particular importance is the…
The H2O abundance of a planetary atmosphere is a powerful indicator of formation conditions. Inferring H2O in the solar system giant planets is challenging, due to condensation depleting the upper atmosphere of water vapour. Substantially…
Gas hydrates are systems of prime importance. In particular, hydrogen hydrates are potential materials of icy satellites and comets, and may be used for hydrogen storage. We explore the H2O-H2 system at pressures in the range 0-100 GPa with…
Recently there has been tremendous increase in the number of identified extra-solar planetary systems. Our understanding of their formation is tied to exoplanet internal structure models, which rely upon equations of state of light elements…
Vitreous GeO$_2$ has been compressed at high temperature, to investigate the effect of thermal activation on the structural reorganization during compression. The measurements were performed in-situ using micro Raman spectroscopy under…
A combination of the extended Ice Rule of Pauling, Raman spectroscopy, and molecular dynamics calculations has enabled us to clarify the bonding origin of the anomalous volume expansion, Raman phonon relaxation, and the stiffness and…
The physicochemical behavior of elements and compounds is heavily altered by high pressure. The occurrence of pressure-induced reactions and phase transitions can be revealed by crystal structure prediction approaches. In this work, we…
First-principles calculations and analysis of the thermodynamic, structural, and electronic properties of liquid SiO$_2$ characterize the bonded-to-atomic transition at 0.1--1.6 TPa and 10$^4$--10$^5$ K (1--7 eV), the high-energy-density…
Hydrogen bond symmetrization is a fundamental pressure-induced transformation in which the distinction between donor and acceptor sites vanishes, resulting in a symmetric hydrogen-bond network. While extensively studied in pure ice, most…
Water (H2O) ice is an important solid constituent of many astrophysical environments. To comprehend the role of such ices in the chemistry and evolution of dense molecular clouds and comets, it is necessary to understand the freeze-out,…
Water is abundant in natural environments but the form it resides in planetary interiors remains uncertain. We report combined synchrotron X-ray diffraction and optical spectroscopy measurements of H2O in the laser-heated diamond anvil cell…
During accretion, the young rocky planets are so hot that they become endowed with a magma ocean. From that moment, the mantle convective thermal flux control the cooling of the planet and an atmosphere is created by outgassing. This…
We report a detailed ab initio investigation on hydrogen bonding, geometry, electronic structure, and lattice dynamics of ice under a large high pressure range, including the ice X phase (55-380GPa), the previous theoretically proposed…
Molecular clouds typically consist of 3/4 H2, 1/4 He and traces of heavier elements. In an earlier work we showed that at very low temperatures and high densities, H2 can be in a phase transition leading to the formation of ice clumps as…
Computational searches for stable and metastable structures of water ice and other H:O compositions at TPa pressures have led us to predict that H$_2$O decomposes into H$_2$O$_2$ and a hydrogen-rich phase at pressures of a little over 5…