Simulating Relaxation Channels of CO2 in Clathrate Nano-cages
Abstract : The energy levels of CO2 in the small (s) and large (l) nano-cages of cubic sI clathrates are calculated in the Born-Oppenheimer approximation using pairwise atom-atom interaction potentials. In the s cage, the centre of mass of CO2 oscillates with small amplitudes, asymmetrically about the cage center with harmonic frequencies around 100 cm-1. In the l cage, oscillations are anharmonic with large amplitude motions in a plane parallel to the hexagonal faces of the cage and the corresponding frequencies are calculated to be 55 cm-1 and 30 cm-1. Librational harmonic frequencies are calculated at 101.7 cm-1 and 56.0 cm-1 in the s cage and at 27.9 cm-1 and 46.4 cm-1 in the l cage. Results show that the coupling between the CO2 molecule and the nano-cage is quite different for the low frequency translational, rotational or librational modes and the high frequency vibrational modes, which consequently leads to different relaxation channels.
Cited literature [7 references]
https://hal-insu.archives-ouvertes.fr/insu-01322154
Contributor : Catherine Cardon <>
Submitted on : Thursday, May 26, 2016 - 4:42:25 PM
Last modification on : Monday, February 10, 2020 - 6:13:46 PM
Document(s) archivé(s) le : Saturday, August 27, 2016 - 10:42:22 AM
Contributor : Catherine Cardon <>
Submitted on : Thursday, May 26, 2016 - 4:42:25 PM
Last modification on : Monday, February 10, 2020 - 6:13:46 PM
Document(s) archivé(s) le : Saturday, August 27, 2016 - 10:42:22 AM
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