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Related papers: Hexagonal structure of phase III of solid hydrogen

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Boron carbide is a ceramic material with unique properties widely used in numerous, including armor, applications. Its mechanical properties, mechanism of compression, and limits of stability are of both scientific and practical value.…

We present a unified view of orientational ordering in phases I, II, and III of solid hydrogen. Phases II and III are orientationally ordered, while the ordering objects in phase II are angular momenta of rotating molecules, and in phase…

Condensed Matter · Physics 2009-10-28 I. I. Mazin , R. J. Hemley , A. F. Goncharov , M. Hanfland , H. -K. Mao

With the motivation of searching for new superconductors in the Mg-B system, we performed ab initio evolutionary searches for all the stable compounds in this binary system in the pressure range of 0-200 GPa. We found previously unknown,…

Superconductivity · Physics 2017-05-24 M. M. Davari Esfahani , Q. Zhu , H. Dong , A. R. Oganov , S. Wang , M. S. Rakitin , X-F. Zhou

The multiple scattering-based theory of Gaspari and Gyorffy for the electron-ion matrix element in close packed metals is applied to Im-3m H3S, which has been predicted by Duan {\it et al.} and Bernstein {\it et al} to be the stable phase…

Superconductivity · Physics 2015-05-28 D. A. Papaconstantopoulos , B. M. Klein , M. J. Mehl , W. E. Pickett

Understanding high-pressure transitions in prototypical linear diatomic molecules, such as hydrogen, nitrogen, and oxygen, is an important objective in high-pressure physics. Recent ultrahigh-pressure study on hydrogen revealed that there…

Materials Science · Physics 2019-10-31 Shan Liu , Meifang Pu , Qiqi Tang , Feng Zhang , Binbin Wu , Li Lei

Most of hydrocarbons are either molecular structures or linear polymeric chains. Discovery of graphene and manufacturing of its monohydride -- graphane incite interest in search for three-dimensional hydrocarbon polymers. However up to now…

Materials Science · Physics 2021-11-30 M. V. Kondrin , V. V. Brazhkin

Hydrogen sulfides have recently received a great deal of interest due to the record high superconducting temperatures of up to 203 K observed on strong compression of dihydrogen sulfide (H2S). A joint theoretical and experimental study is…

The c(6x2) is a reconstruction of the SrTiO3(001) surface that is formed between 1050-1100oC in oxidizing annealing conditions. This work proposes a model for the atomic structure for the c(6x2) obtained through a combination of results…

The collective behavior of vibrated hexagonal disks confined in a monolayer is investigated experimentally. Due to the broken circular symmetry, hexagons prefer to rotate upon sufficiently strong driving. Due to the formation of liquid…

Soft Condensed Matter · Physics 2017-03-29 Manuel Baur , Kai Huang

Structural behavior and equation of state of atomic and molecular crystal phases of dense hydrogen at pressures up to 3.5 TPa are systematically investigated with density functional theory. The results indicate that the Vinet EOS model that…

Other Condensed Matter · Physics 2012-03-27 Hua Y. Geng , Hong X. Song , J. F. Li , Q. Wu

Ab initio random structure searching (AIRSS) and density functional theory methods are used to predict structures of calcium and magnesium carbonate (CaCO$_3$ and MgCO$_3$) at high pressures. We find a previously unknown CaCO$_3$ structure…

Materials Science · Physics 2015-06-22 Chris J. Pickard , Richard J. Needs

Structure of the Ga-stabilized GaAs(001)-c(8x2) surface has been studied using rocking-curve analysis of reflection high-energy electron diffraction (RHEED). The c(8x2) structure emerges at temperatures higher than 600C, but is unstable…

Chemical Physics · Physics 2009-11-07 Akihiro Ohtake , Shiro Tsukamoto , Markus Pristovsek , Nobuyuki Koguchi , Masashi Ozeki

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

A highly stable tungsten triboride with the Pearson symbol hP24 (hP24-WB3) is identified by using density functional theory calculations. This new structure can be derived from the well-known hP3 configuration by removing one third of…

Materials Science · Physics 2013-08-06 Yongcheng Liang , so on

The two published lithium peroxide structures, both ascribed to the hexagonal P -6 space group, were subjected to reinterpretation and another more symmetric structure, now belonging to the P 63/m m c space group, was found. Detailed…

Atomic and Molecular Clusters · Physics 2007-05-23 Luis Guillermo Cota , Pablo de la Mora

Rattling-induced superconductivity in the {\beta}-pyrochlore oxide KOs2O6 is investigated under high pressure up to 5 GPa. Resistivity measurements in a high-quality single crystal reveal a gradual decrease in the superconducting transition…

In this paper we report a new high-pressure rhombohedral phase of Ce2Zr2O8 observed from high-pressure angle-dispersive x-ray diffraction and Raman spectroscopy studies up to nearly 12 GPa. The ambient-pressure cubic phase of Ce2Zr2O8…

Materials Science · Physics 2012-03-12 D. Errandonea , R. S. Kumar , S. N. Achary , O. Gomis , F. J. Manjon , R. Shukla , A. K. Tyagi

Adsorption of hydrogen atoms to a carbon atom vacancy in graphene is investigated by means of periodic \emph{first principles} calculations, up to the fully hydrogenated state where six H atoms chemically bind to the vacancy. Addition of a…

Materials Science · Physics 2013-12-30 M. Casartelli , S. Casolo , G. F. Tantardini , R. Martinazzo

We report equilibrium geometric structures of CuO2, CuO3, CuO6, and CuO clusters obtained by an all-electron linear combination of atomic orbitals scheme within the density-functional theory with generalized gradient approximation to…

Atomic and Molecular Clusters · Physics 2009-11-10 Tunna Baruah , Rajendra R. Zope , Mark R. Pederson

We investigate the van der Waals interactions in solid molecular hydrogen structures. We calculate enthalpy and the Gibbs free energy to obtain zero and finite temperature phase diagrams, respectively. We employ density functional theory…

Materials Science · Physics 2019-05-10 Sam Azadi , Graeme J. Ackland