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Related papers: Ab Initio Simulations of Hot, Dense Methane During…

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Polyhydrides have been shown to form novel structures at high pressure, which may be found in the interiors of giant planets. With density functional molecular dynamics simulations we studied the behavior of ammonium polyhydride compounds…

Materials Science · Physics 2025-12-01 Kyla de Villa , Xiaoyu Wang , Eva Zurek , Burkkhard Militzer

We describe experiments where 2D atomic hydrogen gas is compressed thermally at a small "cold spot" on the surface of superfluid helium and detected directly with electron-spin resonance. We reach surface densities up to 5e12 1/cm^2 at…

Soft Condensed Matter · Physics 2009-11-10 S. Vasilyev , J. Jarvinen , A. I. Safonov , S. Jaakkola

Experiments and computer simulations have shown that the melt-ing temperature of solid hydrogen drops with pressure above about 65 GPa, suggesting that a liquid state might exist at low temperatures. It has also been suggested that this low…

We use path integral Monte Carlo and density functional molecular dynamics to construct a coherent set of equation of state for a series of hydrocarbon materials with various C:H ratios (2:1, 1:1, 2:3, 1:2, and 1:4) over the range of…

Plasma Physics · Physics 2017-07-26 Shuai Zhang , Kevin P. Driver , François Soubiran , Burkhard Militzer

Dielectric response in methanol measured in wide pressure and temperature range ($P < 6.0$ GPa; 100 K $<T<$ 360 K) reveals a series of anomalies which can be interpreted as a transformation between several solid phases of methanol including…

Materials Science · Physics 2015-06-15 M. V. Kondrin , A. A. Pronin , Y. B. Lebed , V. V. Brazhkin

According to the theoretical predictions, insulating molecular hydrogen dissociates and transforms to an atomic metal at pressures P~370-500 GPa. In another scenario, the metallization first occurs in the 250-500 GPa pressure range in…

Materials Science · Physics 2019-06-18 M. I. Eremets , A. P. Drozdov , P. P. Kong , H. Wang

Microwave heating of methane hydrate is investigated with electrostatic molecular dynamics simulations by the SPC/E water model. The structure I of methane hydrate is constructed. When the methane hydrate with a density of 0.91…

Chemical Physics · Physics 2023-11-27 Motohiko Tanaka , Motoyasu Sato , Shin Nakatani

The molecular phase of hydrogen converts to the atomic metallic phase at high pressures estimated usually as 300 - 500 GPa. We analyze the decay of metallic phase as the pressure is relieved below the transition one. The metallic state is…

Other Condensed Matter · Physics 2018-01-03 S. N. Burmistrov , L. B. Dubovskii

In order to provide a comprehensive theoretical description of MgSiO$_3$ at extreme conditions, we combine results from path integral Monte Carlo (PIMC) and density functional molecular dynamics simulations (DFT-MD) and generate a…

Materials Science · Physics 2020-02-19 Felipe González-Cataldo , François Soubiran , Henry Peterson , Burkhard Militzer

We present computational results and tables of the equation-of-state, thermodynamic properties, and shock Hugoniot for hot dense fluid deuterium. The present results are generated using a recently developed chemical model that takes into…

Plasma Physics · Physics 2015-11-26 Mofreh R. Zaghloul

The paper presents an analysis of mechanical, structural, thermophysical and spectral properties of solid methane in temperature interval $0.5T_{tr} -T_{tr}$ ($T_{tr}$ is the triple point temperature) under equilibrium vapor pressure. It is…

Materials Science · Physics 2014-04-30 A. V. Leont'eva , A. Yu. Prokhorov , A. Yu. Zakharov , A. I. Erenburg

Quantum molecular dynamic simulations are introduced to study the dynamical, electrical, and optical properties of carbon dioxide under dynamic compressions. The principal Hugoniot derived from the calculated equation of states is…

Materials Science · Physics 2015-05-19 Cong Wang , Ping Zhang

The interplay between electron correlation and nuclear quantum effects makes our understanding of elemental hydrogen a formidable challenge. Here, we present the phase diagram of hydrogen and deuterium at low temperatures and high-pressure…

Materials Science · Physics 2023-06-28 Lorenzo Monacelli , Michele Casula , Kosuke Nakano , Sandro Sorella , Francesco Mauri

Using quantum molecular dynamic simulations, we have studied the thermophysical properties of warm dense carbon monoxide under extreme conditions. The principal Hugoniot, which is derived from the equation of state, shows excellent…

Materials Science · Physics 2015-05-28 Yu-Juan Zhang , Cong Wang , Da-Fang Li , Ping Zhang

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…

Materials Science · Physics 2012-06-20 Chris J. Pickard , Miguel Martinez-Canales , Richard J. Needs

It has been suggested that hydrogen may metallise at lower pressures if it is ``precompressed''. Here we introduce a search strategy for predicting high-pressure structures and apply it to silane using first-principles electronic structure…

Materials Science · Physics 2009-11-11 Chris J. Pickard , R. J. Needs

In previous work,1 we showed that hydrogen metallizes in phase III at temperatures below ~200 K and at pressures near ~350 GPa. Here, we perform a detailed study of electrical conductivity R(T) in phase III over a pressure range of 200-400…

Materials Science · Physics 2021-09-24 M. I. Eremets , P. P. Kong , A. P. Drozdov

It is generally assumed that solid hydrogen will transform into a metallic alkali-like crystal at sufficiently high pressure. However, some theoretical models have also suggested that compressed hydrogen may form an unusual two-component…

Materials Science · Physics 2009-11-10 Stanimir A. Bonev , Eric Schwegler , Tadashi Ogitsu , Giulia Galli

We perform density functional molecular dynamics simulations of liquid and solid MgSiO3 in the pressure range of 120-1600 GPa and for temperatures up to 20000 K in order to provide new insight into the nature of the liquid-liquid phase…

Materials Science · Physics 2015-06-05 Burkhard Militzer

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…

Materials Science · Physics 2013-02-25 Ioan B. Magdau , Graeme J. Ackland