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Related papers: Molecular hydrogen in silicon: A path-integral sim…

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Molecular dynamics simulations are utilized to study the microwave heating of methane hydrate by the five-body rotation coordinate system with the TIP5P-Ewald model. The structure I of methane hydrate is constructed, and the ice and free…

Chemical Physics · Physics 2024-03-01 Motohiko Tanaka

Silicon presents itself as a high-capacity anode material for lithium-ion batteries with a promising future. The high ability for lithiation comes along with massive volume changes and a problematic voltage hysteresis, causing reduced…

Materials Science · Physics 2024-08-05 Lukas Köbbing , Yannick Kuhn , Birger Horstmann

Several static and dynamic properties of liquid silicon near melting have been determined from an orbital free {\em ab-initio} molecular dynamics simulation. The calculated static structure is in good agreement with the available X-ray and…

Materials Science · Physics 2015-06-25 A. Delisle , D. J. Gonzalez , M. J. Stott

We use molecular dynamics computer simulations to study the equilibrium properties of the surface of amorphous silica. Two types of geometries are investigated: i) clusters with different diameters (13.5\AA, 19\AA, and 26.5\AA) and ii) a…

Statistical Mechanics · Physics 2009-10-31 Alexandra Roder , Walter Kob , Kurt Binder

The temperature equilibration rate in dense hydrogen (for both T_{i}>T_{e} and T_i<T_e) has been calculated with molecular dynamics simulations for temperatures between 10 and 600 eV and densities between 10^{20}/cc to 10^{24}/cc. Careful…

The structure, lattice dynamics and mechanical properties of the magnesium hydroxide have been investigated with static density functional theory calculations as well as \it {ab initio} molecular dynamics. The hypothesis of a superstructure…

We show theoretically that ultracold hydrogen atoms have very favorable properties for sympathetic cooling of molecules to microkelvin temperatures. We calculate the potential energy surfaces for spin-polarized interactions of H atoms with…

Atomic Physics · Physics 2013-11-20 Maykel L. Gonzalez-Martinez , Jeremy M. Hutson

The structural relaxation of pure amorphous silicon (a-Si) and hydrogenated amorphous silicon (a-Si:H) materials, that occurs during thermal annealing experiments, has been analysed by Raman spectroscopy and differential scanning…

Materials Science · Physics 2010-08-02 F. Kail , J. Farjas , P. Roura , C. Secouard , O. Nos , J. Bertomeu , F. Alzina , P. Roca i Cabarrocas

Using empirical potential molecular dynamics we compute dynamical matrix eigenvalues and eigenvectors for a 4096 atom model of amorphous silicon and a set of models with voids of different size based on it. This information is then employed…

Disordered Systems and Neural Networks · Physics 2009-10-31 S. M. Nakhmanson , D. A. Drabold

The thermal characteristics of silicon between 15 and 300 deg K are investigated by applying a computer program on the solution of the differential heat diffusion equation. The computer model is linked to high-purity silicon through a set…

Materials Science · Physics 2007-08-31 H. Diedrich , R. Liberati

We use {\it ab initio} molecular dynamics simulations to study a sample of liquid silica containing 3.84 wt.% H$_2$O.We find that, for temperatures of 3000 K and 3500 K,water is almost exclusively dissolved as hydroxyl groups, the silica…

Disordered Systems and Neural Networks · Physics 2009-11-10 Markus Poehlmann , Magali Benoit , Walter Kob

The dynamics of amorphous silicon at low temperatures can be characterized by a sequence of discrete activated events, through which the topological network is locally reorganized. Using the activation-relaxation technique, we create more…

Condensed Matter · Physics 2009-10-31 G. T. Barkema , Normand Mousseau

The vibrational density of states of silicon nanoparticles in the range from 2.3 to 10.3 nm is studied with the help of molecular-dynamics simulations. From these simulations the vibrational density of states and frequencies of bulk-like…

Materials Science · Physics 2011-01-20 R. Meyer , D. Comtesse

Hydrogen is one of the few molecules which has been incarcerated in the molecular cage of C$_{60}$ and forms endohedral supramolecular complex H$_2$@C$_{60}$. In this confinement hydrogen acquires new properties. Its translational motion…

We deposit intrinsic hydrogenated amorphous silicon (a-Si:H) thin films by reactive pulsed laser deposition, for various hydrogen pressures in the 0-20 Pa range, at a low deposition temperature of 120C, and investigate the hydrogen…

Materials Science · Physics 2017-04-17 A. Mellos , M. Kandyla , D. Palles , M. Kompitsas

Atomic metallic hydrogen has been produced in the laboratory at high pressure and low temperature, prompting further investigations of its different properties. However, purely experimental approaches are infeasible because of the extreme…

Materials Science · Physics 2018-05-29 Bo Peng , Ke Xu , Hao Zhang , Hezhu Shao , Gang Ni , Jing Li , Liangcai Wu , Hongliang Lu , Qingyuan Jin , Heyuan Zhu

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…

Experimental results on the formation of molecular hydrogen on amorphous silicate surfaces are presented for the first time and analyzed using a rate equation model. The energy barriers for the relevant diffusion and desorption processes…

We present an O(N) algorithm to study the vibrational properties of amorphous silicon within the framework of tight-binding approach. The dynamical matrix elements have been evaluated numerically in the harmonic approximation exploiting the…

Disordered Systems and Neural Networks · Physics 2009-11-07 Parthapratim Biswas

The problem of the low-energy highly-anharmonic quantum dynamics of isolated impurities in solids is addressed by using path-integral Monte Carlo simulations. Interstitial oxygen in silicon is studied as a prototypical example showing such…

Condensed Matter · Physics 2009-10-28 Rafael Ramirez , Carlos P. Herrero , Emilio Artacho , Felix Yndurain