Related papers: Anomalous melting behavior of solid hydrogen at hi…
Near 20.48K and in the temperature range 60--70K, anomalous behavior of thermodynamic, spectral, plastic, elastic and other properties of solid methane is observed. The anomalies in the vicinity of 20.48K are due to the phase $\alpha-\beta$…
Equilibrium properties of hydrogen-helium mixtures under conditions similar to the interior of giant gas planets are studied by means of first principle density functional molecular dynamics simulations. We investigate the molecular and…
The noble elements constitute the simplest group of atoms. At low temperatures or high pressures they freeze into the face-centered cubic (fcc) crystal structure (except helium). We perform molecular dynamics using the recently proposed…
We have studied solid hydrogen up to pressures of 300 GPa and temperatures of 350 K using density functional theory methods and have found "mixed structures" that are more stable than those predicted earlier. Mixed structures consist of…
Supersolid is a mysterious and puzzling state of matter whose possible existence has stirred a vigorous debate among physicists for over 60 years. Its elusive nature stems from the coexistence of two seemingly contradicting properties,…
Loubeyre, Occelli, and Dumas (LOD) [1] claim to have produced metallic hydrogen (MH) at a pressure of 425 GPa, without the necessary supporting evidence of an insulator to metal transition. The paper is much ado about nothing. Most of the…
Being the simplest element with just one electron and proton the electronic structure of the Hydrogen atom is known exactly. However, this does not hold for the complex interplay between them in a solid and in particular not at high…
The ground-state properties of spin polarized hydrogen H$\downarrow$ are obtained by means of diffusion Monte Carlo calculations. Using the most accurate to date ab initio H$\downarrow$-H$\downarrow$ interatomic potential we have studied…
The thermodynamic behavior of calcium oxide (\ce{CaO}) under high temperature and pressure conditions is critical for understanding the physics of planetary interiors. This study employs molecular dynamics (MD) simulations, including both…
Theoretical cross sections for the pressure broadening by hydrogen of rotational transitions of water are compared to the latest available measurements in the temperature range 65-220 K. A high accuracy interaction potential is employed in…
Atomic metallic hydrogen has been produced in the laboratory at high pressure and low temperature, prompting further investigations of its different properties. However, purely experimental approaches are infeasible because of the extreme…
Solid rigidity and liquid-scale mobility are thought incompatible in elemental substances. One cannot have an elemental solid that is long-range positionally ordered wherein the atoms flow like in a liquid simultaneously. The only exception…
Understanding the high-pressure behavior of C-H system is of great importance due to its key role in organic, bio-, petroleum and planetary chemistry. We have performed a systematic investigation of the pressure-composition phase diagram of…
It was predicted that solid metallic hydrogen can be obtained if solid molecular hydrogen is pressured to high pressure at low temperature about 80 years ago. Furthermore, the solid metallic hydrogen was theoretically predicted to show…
We study the exciton gas-liquid transition in GaAs/AlGaAs coupled quantum wells. Below a critical temperature, Tc=4.8K, and above a threshold laser power density the system undergoes a phase transition into a liquid state. We determine the…
Much of the interstellar medium in disk galaxies is in the form of neutral atomic hydrogen, H I. This gas can be in thermal equilibrium at relatively low temperatures, T < 300 K (the cold neutral medium, or CNM) or at temperatures somewhat…
A vast amount of Raman spectroscopic data, obtained using diamond anvil cell technique under in situ high pressure-temperature conditions, has been used for mapping the phase transitions of hydrogen in the temperature range of 300 K to 900…
An understanding of hydrogen diffusion on metal surfaces is important, not just for its role in heterogeneous catalysis and hydrogen fuel cell technology, but also because it provides model systems where tunneling can be studied under…
Applying pressure around megabar is indispensable in the synthesis of high-temperature superconducting hydrides, such as SH$_3$ and LaH$_{10}$. Stabilizing the high-pressure phase of hydride around ambient condition is a severe challenge.…
Hydrogen is the most abundant element in the universe. It is also the lightest and as such the most quantum of the elements, in the sense that quantum tunnelling, quantum delocalisation, and zero-point motion can be important. For practical…