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Related papers: Coverage Dependent H$_2$ Desorption Energy: a Quan…

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The remarkably low experimental values of the capacitance data of carbon based materials in contact with water solvent needs to be explained from a microscopic theory in order to optimize the efficiency of these materials. We show that this…

Soft Condensed Matter · Physics 2015-06-04 Sahin Buyukdagli , Tapio Ala-Nissila

The structure of the double-layer formed at the surface of carbon electrodes is governed by the interactions between the electrode and the electrolyte species. However, carbon is notoriously difficult to simulate accurately, even with…

A practical method for finding free energy barriers for transitions in high-dimensional classical and quantum systems is presented and used to calculate the dissociative sticking probability of H2 on a metal surface within transition state…

chem-ph · Physics 2009-10-22 Gregory Mills , Hannes Jonsson

We devise a theoretical description for the response of nitrogen molecules (N2) to ultrashort and intense x rays from the free electron laser (FEL) Linac Coherent Light Source (LCLS). We set out from a rate-equation description for the…

The kinetics of hydrogen absorption by magnesium bulk is affected by two main activated processes: the dissociation of the H$_2$ molecule and the diffusion of atomic H into the bulk. In order to have fast absorption kinetics both activated…

Materials Science · Physics 2008-11-17 Monica Pozzo , Dario Alfe`

We carry out umbrella sampling Monte Carlo simulations to evaluate the free energy surface of the ST2 model of water as a function two order parameters, the density and a bond-orientational order parameter. We approximate the long-range…

Statistical Mechanics · Physics 2013-01-18 Peter H. Poole , Richard K. Bowles , Ivan Saika-Voivod , Francesco Sciortino

It is well known, both theoretically and experimentally, that alloying MgH$_2$ with transition elements can significantly improve the thermodynamic and kinetic properties for H$_2$ desorption, as well as the H$_2$ intake by Mg bulk. Here we…

Materials Science · Physics 2009-11-13 M. Pozzo , D. Alfè , A. Amieiro , S. French , A. Pratt

Ice desorption affects the evolution of the gas-phase chemistry during the protostellar stage, and also determines the chemical composition of comets forming in circumstellar disks. From observations, most volatile species are found in…

Earth and Planetary Astrophysics · Physics 2011-09-01 Edith C. Fayolle , Karin I. Oberg , Herma M. Cuppen , Ruud Visser , Harold Linnartz

For ethylene carbonate on the (100) surface of lithium, we calculate the adsorption energy in two binding motifs as well as the barrier height for a ring-opening decomposition reaction. We validate a scheme for producing results in the…

Context. Interstellar surface chemistry is a complex process that occurs in icy layers accumulated onto grains of different sizes. Efficiency of surface processes often depends on the immediate environment of adsorbed molecules. Aims. We…

Astrophysics of Galaxies · Physics 2024-07-31 Juris Kalvāns , Aija Kalniņa , Kristaps Veitners

The typical amount of molecular hydrogen (${\rm H_2}$) in interstellar ices is not known, but significant freeze-out of ${\rm H_2}$ on dust grains is not expected. However, chemical models ubiquitously predict large amounts of $\rm H_2$…

Astrophysics of Galaxies · Physics 2025-07-03 O. Sipilä , K. Silsbee , N. Carbajal , P. Caselli , M. Padovani

Hydrogenated amorphous carbon (a-C:H) has been proposed as one of the carbonaceous solids detected in the interstellar medium. Energetic processing of the a-C:H particles leads to the dissociation of the C-H bonds and the formation of…

Earth and Planetary Astrophysics · Physics 2016-06-22 Rafael Martín-Doménech , Emmanuel Dartois , Guillermo M. Muñoz Caro

Protoplanetary disks are the target of many chemical studies (both observational and theoretical) as they contain the building material for planets. Their large vertical and radial gradients in density and temperature make them challenging…

Astrophysics of Galaxies · Physics 2016-10-07 V. Wakelam , M. Ruaud , F. Hersant , A. Dutrey , D. Semenov , L. Majumdar , S. Guilloteau

Hydrogen adsorption by the metal organic framework (MOF) structure Zn2(BDC)2(TED) is investigated using a combination of experimental and theoretical methods. By use of the nonempirical van der Waals density-functional (vdW-DF) approach, it…

Materials Science · Physics 2009-11-13 Lingzhu Kong , Valentino R. Cooper , Nour Nijem , Kunhao Li , Jing Li , Yves J. Chabal , David C. Langreth

Theoretical calculations based on density functional theory have made significant contributions to our understanding of metal oxides, their surfaces, and the binding of molecules at these surfaces. In this paper we investigate the binding…

Materials Science · Physics 2007-05-23 Oyvind Borck , Elsebeth Schroder

The difficulty of modeling energy consumption in communication systems leads to challenges in energy harvesting (EH) systems, in which nodes scavenge energy from their environment. An EH receiver must harvest enough energy for demodulating…

Information Theory · Computer Science 2017-04-18 Zhengwei Ni , Mehul Motani

The energy dependence of the rate coefficient of the H$_2^+\ + {\rm H}_2 \rightarrow {\rm H}_3^+ + {\rm H}$ reaction has been measured in the range of collision energies between $k_\mathrm{B}\cdot 10$ K and $k_\mathrm{B}\cdot 300$ mK. A…

An overview is presented of the H$_2$ quasar absorption method to search for a possible variation of the proton--electron mass ratio $\mu=m_p/m_e$ on a cosmological time scale. Details of the analysis of astronomical spectra, obtained with…

Astrophysics of Galaxies · Physics 2016-05-25 Wim Ubachs , Julija Bagdonaite , Edcel J. Salumbides , Michael T. Murphy , Lex Kaper

We report on a many-electron wavefunction theory study for the reaction energetics of hydrogen dissociation on the Si(100) surface. We demonstrate that quantum chemical wavefunction based methods using periodic boundary conditions can…

Materials Science · Physics 2019-01-30 Theodoros Tsatsoulis , Sung Sakong , Axel Groß , Andreas Grüneis

The physical foundations of the dissipation of energy and the associated heating in weakly collisional plasmas are poorly understood. Here, we compare and contrast several measures that have been used to characterize energy dissipation and…