Synthesis of Weaire–Phelan Barium Polyhydride
By combining pressures up to 50 GPa and temperatures of 1200 K, we synthesize the novel barium hydride, Ba8H46, stable down to 27 GPa. We use Raman spectroscopy, X-ray diffraction, and first-principles calculations to determine that this compound adopts a highly symmetric P m 3̅ n structure with an...
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Published in | The journal of physical chemistry letters Vol. 12; no. 20; pp. 4910 - 4916 |
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Main Authors | , , , , , , , , |
Format | Journal Article |
Language | English |
Published |
United States
American Chemical Society
27.05.2021
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Subjects | |
Online Access | Get full text |
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Summary: | By combining pressures up to 50 GPa and temperatures of 1200 K, we synthesize the novel barium hydride, Ba8H46, stable down to 27 GPa. We use Raman spectroscopy, X-ray diffraction, and first-principles calculations to determine that this compound adopts a highly symmetric P m 3̅ n structure with an unusual 5 3 4 :1 hydrogen-to-barium ratio. This singular stoichiometry corresponds to the well-defined type-I clathrate geometry. This clathrate consists of a Weaire–Phelan hydrogen structure with the barium atoms forming a topologically close-packed phase. In particular, the structure is formed by H20 and H24 clathrate cages showing substantially weakened H–H interactions. Density functional theory (DFT) demonstrates that cubic P m 3̅ n Ba8H46 requires dynamical effects to stabilize the H20 and H24 clathrate cages. |
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Bibliography: | ObjectType-Article-1 SourceType-Scholarly Journals-1 ObjectType-Feature-2 content type line 23 |
ISSN: | 1948-7185 1948-7185 |
DOI: | 10.1021/acs.jpclett.1c00826 |