The HD molecule in small and medium cages of clathrate hydrates: Quantum dynamics studied by neutron scattering measurements and computation

Journal Article · Tue Oct 07 00:00:00 EDT 2014 · Journal of Chemical Physics

DOI:https://doi.org/10.1063/1.4896623· OSTI ID:22436562

Colognesi, Daniele; Celli, Milva; Ulivi, Lorenzo ^[1]; Powers, Anna; Xu, Minzhong ^[2]; Bačić, Zlatko ^[2]

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1. Consiglio Nazionale delle Ricerche, Istituto dei Sistemi Complessi, via Madonna del Piano 10, I-50019 Sesto Fiorentino (Italy)
2. Department of Chemistry, New York University, New York, New York 10003 (United States)

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 H{sub 2}) plus methyl tert-butyl ether (MTBE-d12)

• OSTI ID: 22436562
• Journal Information: Journal of Chemical Physics, Vol. 141, Issue 13; Other Information: (c) 2014 AIP Publishing LLC; Country of input: International Atomic Energy Agency (IAEA); ISSN 0021-9606
• Country of Publication: United States
• Language: English

Related Subjects

37 INORGANIC
ORGANIC
PHYSICAL AND ANALYTICAL CHEMISTRY
ANISOTROPY
BUTYL ETHER
CALCULATION METHODS
CLATHRATES
CRYSTAL STRUCTURE
CRYSTALS
HYDRATES
HYDROGEN
HYDROGEN DEUTERIDE
INELASTIC SCATTERING
MOLECULES
MOMENTUM TRANSFER
NEUTRON DIFFRACTION
NEUTRON REACTIONS
NEUTRON SPECTROMETERS
SIMULATION
SPECTRA