相关论文: High-pressure phases of a hydrogen-rich compound: …

Following the idea that hydrogen-rich compounds might be high-T$_c$ superconductors at high pressures, and the very recent breakthrough in predicting and synthesizing hydrogen sulfide with record-high T$_c$ = 203 K, ab initio evolutionary…

Single-crystal synchrotron X-ray diffraction, Raman spectroscopy, and first principles calculations have been used to identify the structure of the high-pressure (HP) phase of molecular methane above 20 GPa up to 71 GPa. The structure of HP…

A study of high pressure solid Te was carried out at room temperature using Raman spectroscopy and Density Functional Theory (DFT) calculations. The analysis of the P-dependence of the experi- mental phonon spectrum reveals the occurrence…

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 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…

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…

The structural and vibrational properties of phenanthrene are measured at high pressures up to 30.2 GPa by Raman spectroscopy and synchrotron x-ray diffraction techniques. Two phase transitions are observed in raman spectra under pressures…

We present a technique for extracting Raman intensities from ab initio molecular dynamics (MD) simulations at high temperature. The method is applied to the highly anharmonic case of dense hydrogen up to 500 K for pressures ranging from 180…

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…

Phase I of hydrogen has several peculiarities. Despite having a close-packed crystal structure, it is less dense than either the low temperature Phase II or the liquid phase. At high pressure, it transforms into either phase III or IV,…

X-ray diffraction (XRD) experiments have been carried out on quartz-like GaPO4 at high pressure and room temperature. A transition to a high pressure disordered crystalline form occurs at 13.5 GPa. Slight heating using a YAG infrared laser…

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…

In this paper, we revisit the high-pressure behavior of BaZrO3 by a combination of first-principle calculations, Raman spectroscopy, and x-ray diffraction under high pressure. We confirm experimentally the cubic-to-tetragonal transition at…

The crystalline structures of lanthanum tetraboride, LaB4, under pressure are investigated using a genetic algorithm method coupled with first-principles calculations. We find two low-enthalpy phases for LaB4 as the thermodynamic ground…

Structural and superconducting transitions of layered van der Waals (vdW) hydrogenated germanene (GeH) were observed under high-pressure compression and decompression processes. GeH possesses a superconducting transition at critical…

Using first-principles variable-composition evolutionary methodology, we explored the high-pressure structures of beryllium hydrides between 0 and 400 GPa. We found that BeH$_2$ remains the only stable compound in this pressure range. The…

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…

Evolutionary algorithms and the particle swarm optimization method have been used to predict stable and metastable high hydrides of iron between 150-300 GPa that have not been discussed in previous studies. Cmca FeH5, Pmma FeH6 and P2/c…

We have carried out a detailed high-pressure investigation on the strongly correlated transition metal chalcogenide $Cr_{3}Te_4$ using Raman spectroscopy and XRD, which is ferromagnetic and metallic at ambient conditions. We find that the…

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…