Structure and dynamics of hydrogen molecules in the novel clathrate hydrate by high pressure neutron diffraction

被引：260

作者：

Lokshin, KA

Zhao, YS

He, DW

Mao, WL

Mao, HK

Hemley, RJ

Lobanov, MV

Greenblatt, M

机构：

[1] Los Alamos Natl Lab, LANSCE 12, Los Alamos, NM 87544 USA

[2] Carnegie Inst Sci, Geophys Lab, Washington, DC 20015 USA

[3] Univ Chicago, Dept Geophys Sci, Chicago, IL 60637 USA

[4] Rutgers State Univ, Dept Chem & Biol Chem, Piscataway, NJ 08854 USA

来源：

PHYSICAL REVIEW LETTERS | 2004年 / 93卷 / 12期

基金：

美国国家科学基金会;

关键词：

D O I：

10.1103/PhysRevLett.93.125503

中图分类号：

O4 [物理学];

学科分类号：

0702 ;

摘要：

The D-2 clathrate hydrate crystal structure was determined as a function of temperature and pressure by neutron diffraction for the first time. The hydrogen occupancy in the (32+X)H-2.136H(2)O, x=0-16 clathrate can be reversibly varied by changing the large (hexakaidecahedral) cage occupancy between two and four molecules, while remaining single occupancy of the small (dodecahedral) cage. Above 130-160 K, the guest D-2 molecules were found in the delocalized state, rotating around the centers of the cages. Decrease of temperature results in rotation freezing followed by a complete localization below 50 K.

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页码：125503 / 1

页数：4

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