TY - JOUR
T1 - The HD molecule in small and medium cages of clathrate hydrates
T2 - Quantum dynamics studied by neutron scattering measurements and computation
AU - Colognesi, Daniele
AU - Powers, Anna
AU - Celli, Milva
AU - Xu, Minzhong
AU - Bačić, Zlatko
AU - Ulivi, Lorenzo
N1 - Publisher Copyright:
© 2014 AIP Publishing LLC.
PY - 2014/10/7
Y1 - 2014/10/7
N2 - We report inelastic neutron scattering (INS) measurements on molecular hydrogen deuteride (HD) trapped in binary cubic (sII) and hexagonal (sH) clathrate hydrates, performed at low temperature using two different neutron spectrometers in order to probe both energy and momentum transfer. The INS spectra of binary clathrate samples exhibit a rich structure containing sharp bands arising from both the rotational transitions and the rattling modes of the guest molecule. For the clathrates with sII structure, there is a very good agreement with the rigorous fully quantum simulations which account for the subtle effects of the anisotropy, angular and radial, of the host cage on the HD microscopic dynamics. The sH clathrate sample presents a much greater challenge, due to the uncertainties regarding the crystal structure, which is known only for similar crystals with different promoter, but nor for HD (or H2) plus methyl tert-butyl ether (MTBE-d12).
AB - We report inelastic neutron scattering (INS) measurements on molecular hydrogen deuteride (HD) trapped in binary cubic (sII) and hexagonal (sH) clathrate hydrates, performed at low temperature using two different neutron spectrometers in order to probe both energy and momentum transfer. The INS spectra of binary clathrate samples exhibit a rich structure containing sharp bands arising from both the rotational transitions and the rattling modes of the guest molecule. For the clathrates with sII structure, there is a very good agreement with the rigorous fully quantum simulations which account for the subtle effects of the anisotropy, angular and radial, of the host cage on the HD microscopic dynamics. The sH clathrate sample presents a much greater challenge, due to the uncertainties regarding the crystal structure, which is known only for similar crystals with different promoter, but nor for HD (or H2) plus methyl tert-butyl ether (MTBE-d12).
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U2 - 10.1063/1.4896623
DO - 10.1063/1.4896623
M3 - Article
AN - SCOPUS:84907735193
SN - 0021-9606
VL - 141
JO - Journal of Chemical Physics
JF - Journal of Chemical Physics
IS - 13
M1 - 134501
ER -