Molecular dynamics methane

The CH cation 1, protonated methane, is the parent of hypercoordinated carbocations containing a five coordinated carbon atom. It is elusive in solution and has not been observed by NMR spectroscopy but gas-phase infrared investigations have shown its fluxional structure which has been proven by ab initio molecular dynamic simulation.18... 

Tight-binding Molecular Dynamics of Shock Waves in Methane. 

Methane Hydrate Formation via Molecular Dynamics Simulations. J Am. Chem. Soc., 127, 17852-17862. 

The above molecular dynamics results have been confirmed by incoherent inelastic neutron scattering (IINS) measurements on xenon hydrate (Tse et al., 2001 Gutt et al., 2002). In earlier measurements on methane hydrate, the dominant... 

Molecular dynamics (MD) simulation studies also indicate that the initial formation of methane hydrate occurs preferentially near the water-methane interface where there is a significant concentration gradient (Moon et al., 2003). 

As in the molecular dynamic calculations, MC calculations for water structures were first tested against experimental values. Beveridge and coworkers (Swaminathan et al., 1978) and Owicki and Scheraga (1977) obtained acceptable comparison of their calculations against experimental values for the oxygen-oxygen radial distribution function for both water and methane dissolved in water. 

Figure 2.4 Simulated trajectories of helium, oxygen and methane molecules during a 200-ps time period in a poly(dimethylsiloxane) matrix [9]. Reprinted with permission from S.G. Charati and S.A. Stern, Diffusion of Gases in Silicone Polymers Molecular Dynamic Simulations, Macromolecules 31, 5529. Copyright 1998, American Chemical Society...

Molecular dynamics study of the conversion of methane to diamond under pressure Scandolo S, Jeanloz R (2003) American Scientist 91 516... 

N.J. English et al., Molecular-dynamics simulations of methane hydrate dissociation. J. Chem. Phys. 123, 244503 (2005)... 

Molecular-dynamic simulations are characterized by a solution of Newton s laws of motion for the molecules travelling through the zeolite pore system under control of the force field given by the properties of the host lattice, by interactions between the host and the molecules, and by interactions between the molecules. To date this has been possible only for the diffusion of simple molecules (e.g. methane or benzene) inside a zeolite lattice of limited dimensions [29, 37, 54], To take into account the effects of a chemical reaction as well would require quantum-mechanical considerations however, such simulations are in their infancy. 

Molecular mechanics (MM), molecular dynamics (MD), and Monte-Carlo (MC) methods were employed to simulate the adsorption of methane, ethane, propane and isobutane on silicalite and HZSM-5. The silicalite was simulated using the same cluster-model adopted in the diffusion calculations. The H-ZMS-5 structure was constructed according to the procedure suggested by Vetrivel et al. [32], which consists in replacing one atom at the channel intersection by and protonating the oxygen atom bridging the Ta and Tg sites in order to preserve the lattice neutrality. 

In the molecular dynamics calculations the trajectories of methane molecules in the pore are followed using the equation of motion with appropriate temperature control. A diffuse reflection condition is applied at the pore wall. For the EMD simulations a collective transport coefficient obtained from autocorrelation of the fluctuating axial streaming velocity via a Green-Kubo relation [S]... 

A. Laaksonen and P. Stilbs, Molecular Dynamics and NMR Study of Methane-Water Systems, Mol. Phys., 74 (1991), 747. 

A. Alavi, Molecular Dynamics Simulation of Methane Adsorbed in MgO Evidence for a Kosterlitz-Thouless Transition, Mol. Phys. 71 (1990) 1173-1191 Evidence for a Kosterlitz-Thouless Transition in a Simulation of CD4 Adsorbed on MgO, Phys. Rev. Lett. 64 (1990), 2289-2292. A. Alavi and I. R. McDonald, Molecular Dynamics Simulation of Argon Physisorbed on Magnesium Oxide, Mol. Phys. 69 (1990) 703-713. 

R. F. Cracknell, D. Nicholson and K. E. Gubbins, Molecular Dynamics Study of the Self-Diffusion of Supercritical Methane in Slit-shaped Graphitic Micropores, J. Chem. Soc. Faraday Trans. 91 (1995) 1377-1383. 

D. van Belle and S. Wodak, Molecular Dynamics Study in Methane Hydration and Methane Association in A Polarizable Water Phase, J. Am. Chem. Soc. 115 (1993) 647. 

Jost S, Bar NK, Fritzsche S, Haberlandt R, and Karger J. Diffusion of a mixture of methane and xenon in silicalite A molecular dynamics study and pulsed field gradient nuclear magnetic resonance experiments. J Phys Chem B 1998 102 6375-6381. 

K. S. Smirnov and B. van de Graaf,/. Chem. Soc., Faraday Trans., 92,2475 (1996). Study of Methane Adsorption in MFI and MEL Zeolites by Combination of the Electronegativity Equalization Method and Molecular Dynamics. 

Molecular dynamics simulations for the mixture water (1) + methane (2) + sodium chloride (3) revealed a similar local structure around an infinitely dilute gas molecule, namely the methane molecule is preferentially hydrated and sodium chloride is preferentially excluded from the vicinity of a methane molecule [72]. 

In the present paper, the method which the authors employed previously to derive an expression for the solubility of various proteins in aqueous solutions, has been extended to the solubility of gases in mixtures of water + strong electrolytes. One parameter equation for the solubility of gases has been derived, which was used to represent the solubilities of oxygen, carbon dioxide and methane in water -i- sodium chloride. In additions, the developed theory could be used to examine the local composition of the solvent around a gas molecule. The results revealed that the oxygen, carbon dioxide and methane molecules are preferentially hydrated in water-i-sodium chloride mixtures. A similar result was obtained for the water -i- methane -i- sodium chloride by molecular dynamics simulations [72]. 

Another approach to investigate the hydrophobic effect is the ab initio quantum mechanical technique." " It is based on first principles (the Schrodinger equation), and this constitutes its main advantage compared to molecular dynamics and Monte Carlo approaches, which are based on classical potentials. At the present time, the ab initio quantum mechanical methods have limitations connected to the complexity and size of the molecular clusters considered." Nevertheless, these methods have been often used to accurately predict the structure and energy of a system of two molecules (dimers), " such as the system methane/water." " However, the structure and energy of a... 

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