English
Related papers

Related papers: The structure in warm dense carbon

200 papers

The electronic structure and dielectric properties of the diamond, body centered cubic diamond (bc8), and hexagonal diamond (lonsdaleite) phases of carbon are computed using density functional theory and many-body perturbation theory with…

Materials Science · Physics 2022-03-14 Kushal Ramakrishna , Jan Vorberger

We applied single-crystal X-ray diffraction and Raman spectroscopy in a diamond anvil cell up to 36 GPa and first principles theoretical calculations to study the molecular dissociation of solid iodine at high pressure. Unlike previously…

The crystal structure of iron in the Earth's inner core remains debated. Most recent experiments suggest a hexagonal-close-packed (hcp) phase. In simulations, it has been generally agreed that the hcp-Fe is stable at inner core pressures…

Geophysics · Physics 2018-04-17 Rostislav Hrubiak , Yue Meng , Guoyin Shen

The equations of state at room temperature as well as the energies of crystal structures up to pressures exceeding 100 GPa are calculated for Na and K . It is shown that the allowance for generalized gradient corrections (GGA) in the…

Materials Science · Physics 2009-10-31 M. I. Katsnelson , G. V. Sinko , N. A. Smirnov , A. V. Trefilov , K. Yu. Khromov

Noting the structural relationships between phases of carbon and boron carbide with phases of boron nitride and boron subnitride, we investigate their mutual solubilities using a combination of first principles total energies supplemented…

Materials Science · Physics 2016-04-13 Hantao Zhang , Sanxi Yao , Michael Widom

The complex crystal chemistry of elemental boron has led to numerous proposed structures with distinctive motifs as well as contradictory findings. Herein, evolutionary structure searches performed at 100 GPa have uncovered a series of…

Materials Science · Physics 2021-05-19 Katerina P. Hilleke , Eva Zurek , Tadashi Ogitsu , Shuai Zhang

The observed "simple cubic" (sc) phase of elemental Ca at room temperature in the 32-109 GPa range is, from linear response calculations, dynamically unstable. By comparing first principle calculations of the enthalpy for five sc-related…

Superconductivity · Physics 2009-12-01 Z. P. Yin , F. Gygi , W. E. Pickett

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…

Materials Science · Physics 2022-01-12 I. Saitov

Density-functional calculations are presented for high-pressure structural phases of S and Se. The structural phase diagrams, phonon spectra, electron-phonon coupling, and superconducting properties of the isovalent elements are compared.…

Condensed Matter · Physics 2009-10-31 Sven P. Rudin , Amy Y. Liu , J. K. Freericks , A. Quandt

Density Functional Theory calculations using the quasi-harmonic approximation have been used to calculate the solid Hugoniot of two polytypes of boron carbide up to 100 GPa. Under the assumption that segregation into the elemental phases…

Materials Science · Physics 2017-06-28 Andrew Shamp , Eva Zurek , Tadashi Ogitsu , Dayne E. Fratanduono , Sebastien Hamel

Structural correlations at a liquid-solid interface were explored with molecular dynamics simulations of a model aluminium system using the Ercolessi-Adams potential and up to 4320 atoms. Substrate atoms were pinned to their equilibrium…

Materials Science · Physics 2007-05-23 Adham Hashibon , Joan Adler , Michael W. Finnis , Wayne D. Kaplan

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…

Materials Science · Physics 2015-05-20 Jeffrey M. McMahon , David M. Ceperley

We have studied the evolution, with hydrostatic pressure, of the recently discovered superconductivity in the graphite intercalation compounds C$_6$Yb and C$_6$Ca. We present pressure-temperature phase diagrams, for both superconductors,…

Computational searches for structures of solid oxygen under pressures in the multi TPa range have been carried out using density-functional-theory methods. We find that molecular oxygen persists to about 1.9 TPa at which it transforms into…

Materials Science · Physics 2012-07-06 Jian Sun , Miguel Martinez-Canales , Dennis D. Klug , Chris J. Pickard , Richard J. Needs

Understanding the phase behaviors of nanoconfined water has driven notable research interests recently. In this work, we examine the structures and thermodynamics of water encapsulated under a graphene cover. We find layered water…

Statistical Mechanics · Physics 2016-07-19 Shuping Jiao , Chuanhua Duan , Zhiping Xu

We report on the phase behavior of an aqueous binary charged sphere suspension under exhaustively deionized conditions as a function of number fraction of small particles p and total number density n. The mixture of size ratio 0.557…

Soft Condensed Matter · Physics 2010-05-19 Nina J. Lorenz , Hans Joachim Schoepe , Thomas Palberg

We used ab initio random structure searching (AIRSS) to investigate polymorphism in C3N4 carbon nitride as a function of pressure. Our calculations reveal new framework structures, including a particularly stable chiral polymorph of space…

Materials Science · Physics 2016-09-14 Chris J. Pickard , Ashkan Salamat , Michael J. Bojdys , Richard J. Needs , Paul F. McMillan

The recent reports on high-temperature superconductivity above 190 K in hydrogen sulfide at 200 GPa pressure, exceeding all previously discovered superconductors, has greatly invigorated the interest in dense hydrogen-rich solids. In this…

Superconductivity · Physics 2015-09-02 Christoph Heil , Lilia Boeri

The pressure-induced transformation of diatomic nitrogen into non-molecular polymeric phases may produce potentially useful high-energy-density materials. We combine first-principles calculations with structure searching to predict a new…

Materials Science · Physics 2015-09-30 Yinwei Li , Jian Hao , Hanyu Liu , Siyu Lu , John S. Tse

We study the structural and thermodynamic properties of bilayer graphene, a prototype two-layer membrane, by means of Monte Carlo simulations based on the empirical bond order potential LCBOPII. We present the temperature dependence of…

Materials Science · Physics 2015-05-18 K. V. Zakharchenko , J. H. Los , M. I. Katsnelson , A. Fasolino