Methane clathrate: CH4 quantum rotor state dependent rattling potential
In methane hydrate the dominant peak in the density of states above 3meV represents a rattling mode of the guest molecule CH4 in the large ice cages. This mode shifts from 6.7meV at T=4.5K to T=30K to 7.14meV with conversion of CH4 guest molecules into the tunneling ground state. The less symmetric...
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craippubl:10.1063/1.2400031 2024-06-23T07:54:37+00:00 Methane clathrate: CH4 quantum rotor state dependent rattling potential Prager, M. Press, W. 2006 http://dx.doi.org/10.1063/1.2400031 https://pubs.aip.org/aip/jcp/article-pdf/doi/10.1063/1.2400031/14738066/214703_1_online.pdf en eng AIP Publishing The Journal of Chemical Physics volume 125, issue 21 ISSN 0021-9606 1089-7690 journal-article 2006 craippubl https://doi.org/10.1063/1.2400031 2024-06-06T04:04:17Z In methane hydrate the dominant peak in the density of states above 3meV represents a rattling mode of the guest molecule CH4 in the large ice cages. This mode shifts from 6.7meV at T=4.5K to T=30K to 7.14meV with conversion of CH4 guest molecules into the tunneling ground state. The less symmetric angular density distribution ΨΨ* in the excited rotational state compared to the ground state allows the methane to fit better in the orientation dependent cage potential surface. This leads to a larger average distance to the cage-forming molecules with a weaker potential and a reduced rattling energy. A two state single particle model with characteristic rattling energies of 5.20meV for pure T-methane and 7.3meV for pure A-methane weighted by the population factors can fit the data. Article in Journal/Newspaper Methane hydrate AIP Publishing The Journal of Chemical Physics 125 21 |
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AIP Publishing |
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English |
description |
In methane hydrate the dominant peak in the density of states above 3meV represents a rattling mode of the guest molecule CH4 in the large ice cages. This mode shifts from 6.7meV at T=4.5K to T=30K to 7.14meV with conversion of CH4 guest molecules into the tunneling ground state. The less symmetric angular density distribution ΨΨ* in the excited rotational state compared to the ground state allows the methane to fit better in the orientation dependent cage potential surface. This leads to a larger average distance to the cage-forming molecules with a weaker potential and a reduced rattling energy. A two state single particle model with characteristic rattling energies of 5.20meV for pure T-methane and 7.3meV for pure A-methane weighted by the population factors can fit the data. |
format |
Article in Journal/Newspaper |
author |
Prager, M. Press, W. |
spellingShingle |
Prager, M. Press, W. Methane clathrate: CH4 quantum rotor state dependent rattling potential |
author_facet |
Prager, M. Press, W. |
author_sort |
Prager, M. |
title |
Methane clathrate: CH4 quantum rotor state dependent rattling potential |
title_short |
Methane clathrate: CH4 quantum rotor state dependent rattling potential |
title_full |
Methane clathrate: CH4 quantum rotor state dependent rattling potential |
title_fullStr |
Methane clathrate: CH4 quantum rotor state dependent rattling potential |
title_full_unstemmed |
Methane clathrate: CH4 quantum rotor state dependent rattling potential |
title_sort |
methane clathrate: ch4 quantum rotor state dependent rattling potential |
publisher |
AIP Publishing |
publishDate |
2006 |
url |
http://dx.doi.org/10.1063/1.2400031 https://pubs.aip.org/aip/jcp/article-pdf/doi/10.1063/1.2400031/14738066/214703_1_online.pdf |
genre |
Methane hydrate |
genre_facet |
Methane hydrate |
op_source |
The Journal of Chemical Physics volume 125, issue 21 ISSN 0021-9606 1089-7690 |
op_doi |
https://doi.org/10.1063/1.2400031 |
container_title |
The Journal of Chemical Physics |
container_volume |
125 |
container_issue |
21 |
_version_ |
1802646825431203840 |