Molecular dynamics simulation study of the properties of doubly occupied N2 clathrate hydrates
| Autor: | Jan A. Schouten, J. P. J. Michels, John S. Tse, E. P. van Klaveren, D. D. Klug |
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| Přispěvatelé: | WZI (IoP, FNWI) |
| Rok vydání: | 2001 |
| Předmět: |
Chemistry
Clathrate hydrate Neutron diffraction General Physics and Astronomy Radial distribution nitrogen Molecular dynamics symbols.namesake molecular dynamics method order-disorder transformations Molecular vibration symbols digital simulation Molecule Raman spectra Physical and Theoretical Chemistry Atomic physics Raman spectroscopy vibrational states |
| Zdroj: | Journal of Chemical Physics, 115, 10500-10508. American Institute of Physics |
| ISSN: | 1089-7690 0021-9606 |
| Popis: | We have performed molecular dynamics calculations to obtain a number of properties of a doubly occupied structure II N2 clathrate hydrate, in particular to study its behavior under higher pressures. The calculated neutron diffraction pattern is in agreement with the experimental result. The effect of the presence of the filling of the small cages and of the large cages (in either single or double occupancy) on the calculated pattern is demonstrated and discussed. The calculated Raman spectra show that the average vibrational frequency of the N2 molecules decreases in going from the singly occupied small cages to the doubly occupied large cages and then to the singly occupied large cages, respectively. The frequency distributions are explained in terms of radial distribution functions. When applying large pressures at low temperatures, a clathrate-amorphous transition occurs for a partially doubly occupied clathrate. The transition occurs at about the same pressure as for single occupations, but the densification is larger for the latter. In both cases, the transition is reversible. |
| Databáze: | OpenAIRE |
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