Related papers: Structural and electronic properties of solid mole…
We have studied dense hydrogen and deuterium experimentally up to 320 GPa and using ab initio molecular dynamic (MD) simulations up to 370 GPa between 250 and 300 K. Raman and optical absorption spectra show significant anharmonic and…
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…
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 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…
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…
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…
We present an accurate computational study of the electronic structure and lattice dynamics of solid molecular hydrogen at high pressure. The band-gap energies of the $C2/c$, $Pc$, and $P6_3/m$ structures at pressures of 250, 300, and 350…
The hydrogen phase diagram has a number of unusual features which are generally well reproduced by density functional calculations. Unfortunately, these calculations fail to provide good physical insights into why those features occur. In…
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…
We present an accurate study of the static-nucleus electronic energy band gap of solid molecular hydrogen at high pressure. The excitonic and quasiparticle gaps of the $C2/c$, $Pc$, $Pbcn$, and $P6_3/m$ structures at pressures of 250, 300,…
By performing constant-pressure variable-cell ab initio molecular dynamics simulations we find a quadrupolar orthorhombic structure, of $Pca2_1$ symmetry, for the broken symmetry phase (phase II) of solid H2 at T=0 and P =110 - 150 GPa. We…
A recent experimental study of the metallization of hydrogen tracked the direct band gap and vibron frequency via infrared measurements up to ~425 GPa [P. Loubeyre et al., Nature 577, 631 (2020)]. Above this pressure, the direct gap has a…
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…
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…
We present results predicting experimentally measurable structural quantities from molecular dynamics studies of hydrogen. In doing this, we propose a paradigm shift for experimentalists -- that the predictions from such calculations should…
The electronic properties of hydrogenated graphenes are investigated with the first-principles calculations. Geometric structures, energy bands, charge distributions, and density of states (DOS) strongly depend on the different…
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…
Alkali metals display unexpected properties at high pressure, including emergence of low symmetry crystal structures, that appear to occur due to enhanced electronic correlations among the otherwise nearly-free conduction electrons. We…
The electronic structure and structural evolution of hydrogenated graphene are investigated by Raman spectroscopy with multiple excitations. The excitation energy dependent saturation effect on the ratio of integrated intensities of D and G…
We report a density-functional theory study of the structural and electronic properties of Cd2V2O7 under high-pressure conditions. The calculations have been performed by using first-principle calculations with the CRYSTAL program. The…