First principles molecular dynamics study of filled ice hydrogen hydrate
We investigated structural changes, phase diagram, and vibrational properties of hydrogen hydrate in filled-ice phase C2 by using first principles molecular dynamics simulation. It was found that the experimentally reported 'cubic' structure is unstable at low temperature and/or high press...
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ftdatacite:10.48550/arxiv.1208.4406 2023-05-15T17:12:05+02:00 First principles molecular dynamics study of filled ice hydrogen hydrate Zhang, Jingyun Kuo, Jer-Lai Iitaka, Toshiaki 2012 https://dx.doi.org/10.48550/arxiv.1208.4406 https://arxiv.org/abs/1208.4406 unknown arXiv https://dx.doi.org/10.1063/1.4746776 arXiv.org perpetual, non-exclusive license http://arxiv.org/licenses/nonexclusive-distrib/1.0/ Materials Science cond-mat.mtrl-sci Chemical Physics physics.chem-ph FOS Physical sciences article-journal Article ScholarlyArticle Text 2012 ftdatacite https://doi.org/10.48550/arxiv.1208.4406 https://doi.org/10.1063/1.4746776 2022-04-01T13:42:08Z We investigated structural changes, phase diagram, and vibrational properties of hydrogen hydrate in filled-ice phase C2 by using first principles molecular dynamics simulation. It was found that the experimentally reported 'cubic' structure is unstable at low temperature and/or high pressure. The 'cubic' structure reflects the symmetry at high (room) temperature where the hydrogen bond network is disordered and the hydrogen molecules are orientationally disordered due to thermal rotation. In this sense, the 'cubic' symmetry would definitely be lowered at low temperature where the hydrogen bond network and the hydrogen molecules are expected to be ordered. At room temperature and below 30 GPa, it is the thermal effects that play an essential role in stabilizing the structure in 'cubic' symmetry. Above 60 GPa, the hydrogen bonds in the framework would be symmetrized and the hydrogen bond order-disorder transition would disappear. These results also suggest the phase behavior of other filled-ice hydrates. In the case of rare gas hydrate, there would be no guest molecues rotation-nonrotation transition since the guest molecules keep their spherical symmetry at any temperature. On the contrary methane hydrate MH-III would show complex transitions due to the lower symmetry of the guest molecule. These results would encourage further experimental studies, especially NMR spectroscopy and neutron scattering, on the phases of filled-ice hydrates at high pressures and/or low temperatures. : typos corrected Text Methane hydrate DataCite Metadata Store (German National Library of Science and Technology) |
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Materials Science cond-mat.mtrl-sci Chemical Physics physics.chem-ph FOS Physical sciences |
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Materials Science cond-mat.mtrl-sci Chemical Physics physics.chem-ph FOS Physical sciences Zhang, Jingyun Kuo, Jer-Lai Iitaka, Toshiaki First principles molecular dynamics study of filled ice hydrogen hydrate |
topic_facet |
Materials Science cond-mat.mtrl-sci Chemical Physics physics.chem-ph FOS Physical sciences |
description |
We investigated structural changes, phase diagram, and vibrational properties of hydrogen hydrate in filled-ice phase C2 by using first principles molecular dynamics simulation. It was found that the experimentally reported 'cubic' structure is unstable at low temperature and/or high pressure. The 'cubic' structure reflects the symmetry at high (room) temperature where the hydrogen bond network is disordered and the hydrogen molecules are orientationally disordered due to thermal rotation. In this sense, the 'cubic' symmetry would definitely be lowered at low temperature where the hydrogen bond network and the hydrogen molecules are expected to be ordered. At room temperature and below 30 GPa, it is the thermal effects that play an essential role in stabilizing the structure in 'cubic' symmetry. Above 60 GPa, the hydrogen bonds in the framework would be symmetrized and the hydrogen bond order-disorder transition would disappear. These results also suggest the phase behavior of other filled-ice hydrates. In the case of rare gas hydrate, there would be no guest molecues rotation-nonrotation transition since the guest molecules keep their spherical symmetry at any temperature. On the contrary methane hydrate MH-III would show complex transitions due to the lower symmetry of the guest molecule. These results would encourage further experimental studies, especially NMR spectroscopy and neutron scattering, on the phases of filled-ice hydrates at high pressures and/or low temperatures. : typos corrected |
format |
Text |
author |
Zhang, Jingyun Kuo, Jer-Lai Iitaka, Toshiaki |
author_facet |
Zhang, Jingyun Kuo, Jer-Lai Iitaka, Toshiaki |
author_sort |
Zhang, Jingyun |
title |
First principles molecular dynamics study of filled ice hydrogen hydrate |
title_short |
First principles molecular dynamics study of filled ice hydrogen hydrate |
title_full |
First principles molecular dynamics study of filled ice hydrogen hydrate |
title_fullStr |
First principles molecular dynamics study of filled ice hydrogen hydrate |
title_full_unstemmed |
First principles molecular dynamics study of filled ice hydrogen hydrate |
title_sort |
first principles molecular dynamics study of filled ice hydrogen hydrate |
publisher |
arXiv |
publishDate |
2012 |
url |
https://dx.doi.org/10.48550/arxiv.1208.4406 https://arxiv.org/abs/1208.4406 |
genre |
Methane hydrate |
genre_facet |
Methane hydrate |
op_relation |
https://dx.doi.org/10.1063/1.4746776 |
op_rights |
arXiv.org perpetual, non-exclusive license http://arxiv.org/licenses/nonexclusive-distrib/1.0/ |
op_doi |
https://doi.org/10.48550/arxiv.1208.4406 https://doi.org/10.1063/1.4746776 |
_version_ |
1766068853020819456 |