Related papers: Quasi-molecular and atomic phases of dense solid h…
Identifying the atomic structure and properties of solid hydrogen under high pressures is a long-standing problem of high-pressure physics with far-reaching significance in planetary and materials science. Determining the…
Experimental progress finally reached the metallic solid hydrogen phase, which was predicted by Wigner and Huntington over 80 years ago. However, the different structures in the phase diagram are still been debated due to the difficulty of…
By employing first-principles metadynamics simulations, we explore the 300 K structures of solid hydrogen over the pressure range 150-300 GPa. At 200 GPa, we find the ambient-pressure disordered hexagonal close-packed (hcp) phase transited…
Hydrogen is the most abundant element in the universe, and its properties under conditions of high temperature and pressure are crucial to understand the interior of of large gaseous planets and other astrophysical bodies. At ultra high…
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…
A hexagonal structure of solid molecular hydrogen with $P6_122$ symmetry is calculated to be more stable below about 200 GPa than the monoclinic $C2/c$ structure identified previously as the best candidate for phase III. We find that the…
We reassess the phase diagram of high-pressure solid hydrogen using mean-field and many-body wave function based approaches to determine the nature of phase III of solid hydrogen. To discover the best candidates for phase III, density…
The phase diagram of hydrogen is one of the most important challenges in high-pressure physics and astrophysics. Especially, the melting of dense hydrogen is complicated by dimer dissociation, metallization and nuclear quantum effect of…
Recent experimental developments in hydrogen-rich materials in high pressures have put this class of materials above others in the race toward room temperature superconductivity. As it is the basis of all the materials in this class, the…
Solid CS$_{2}$ is superficially similar to CO$_{2}$, with the same $Cmca$ molecular crystal structure at low pressures, which has suggested similar phases also at high pressures. We carried out an extensive first principles evolutionary…
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…
The Mg-Si-O system is the major Earth and rocky planet-forming system. Here, through quantum variable-composition evolutionary structure explorations, we have discovered several unexpected stable binary and ternary compounds in the Mg-Si-O…
We study the structural and electronic properties of phase III of solid hydrogen using accurate many-electron theories and compare to state-of-the-art experimental findings. The atomic structures of phase III modelled by C2/c-24 crystals…
The stability of high-pressure phases of hydrogen remains a central question in condensed matter physics, where both experimental observations and theoretical predictions are highly sensitive to methodological choices. Here, we revisit the…
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,…
We propose three new phases of H2O under ultrahigh pressure. Our structural search was performed using an adaptive genetic algorithm which allows an extensive exploration of crystal structure. The new sequence of pressure-induced…
Ab initio molecular dynamic method within the framework of density functional theory is applied to analyze the structural and electronic properties of crystalline molecular hydrogen at temperature 100\,K. Pressure, pair correlation function…
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…
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 high-pressure II-III phase transition in solid hydrogen is investigated using the random phase approximation and diffusion Monte Carlo. Good agreement between the methods is found confirming that an accurate treatment of exchange and…