Search NASA⌕ Search

DOE OSTI · 1720438

Materials Data on Ba8U3(HgS6)3 by Materials Project

Abstract

Ba8U3(HgS6)3 crystallizes in the hexagonal P-6 space group. The structure is three-dimensional. there are eight inequivalent Ba2+ sites. In the first Ba2+ site, Ba2+ is bonded in a 8-coordinate geometry to eight S2- atoms. There are a spread of Ba–S bond distances ranging from 3.17–3.55 Å. In the second Ba2+ site, Ba2+ is bonded in a 8-coordinate geometry to eight S2- atoms. There are a spread of Ba–S bond distances ranging from 3.18–3.51 Å. In the third Ba2+ site, Ba2+ is bonded in a 8-coordinate geometry to eight S2- atoms. There are a spread of Ba–S bond distances ranging from 3.16–3.57 Å. In the fourth Ba2+ site, Ba2+ is bonded to seven S2- atoms to form distorted BaS7 pentagonal bipyramids that share corners with two equivalent BaS7 pentagonal bipyramids, edges with two equivalent US6 octahedra, an edgeedge with one BaS7 pentagonal bipyramid, and faces with two equivalent BaS7 pentagonal bipyramids. There are a spread of Ba–S bond distances ranging from 3.14–3.36 Å. In the fifth Ba2+ site, Ba2+ is bonded in a 8-coordinate geometry to eight S2- atoms. There are a spread of Ba–S bond distances ranging from 3.20–3.41 Å. In the sixth Ba2+ site, Ba2+ is bonded to seven S2- atoms to form distorted BaS7 pentagonal bipyramids that share corners with two equivalent BaS7 pentagonal bipyramids, edges with two equivalent US6 octahedra, an edgeedge with one BaS7 pentagonal bipyramid, and faces with two equivalent BaS7 pentagonal bipyramids. There are a spread of Ba–S bond distances ranging from 3.17–3.24 Å. In the seventh Ba2+ site, Ba2+ is bonded in a 8-coordinate geometry to eight S2- atoms. There are a spread of Ba–S bond distances ranging from 3.16–3.59 Å. In the eighth Ba2+ site, Ba2+ is bonded in a 8-coordinate geometry to eight S2- atoms. There are a spread of Ba–S bond distances ranging from 3.17–3.55 Å. There are three inequivalent U+4.67+ sites. In the first U+4.67+ site, U+4.67+ is bonded to six S2- atoms to form edge-sharing US6 octahedra. There are a spread of U–S bond distances ranging from 2.59–2.72 Å. In the second U+4.67+ site, U+4.67+ is bonded to six S2- atoms to form US6 octahedra that share edges with two equivalent US6 octahedra and edges with two equivalent BaS7 pentagonal bipyramids. There are a spread of U–S bond distances ranging from 2.59–2.73 Å. In the third U+4.67+ site, U+4.67+ is bonded to six S2- atoms to form US6 octahedra that share edges with two equivalent US6 octahedra and edges with two equivalent BaS7 pentagonal bipyramids. There are a spread of U–S bond distances ranging from 2.56–2.72 Å. There are three inequivalent Hg2+ sites. In the first Hg2+ site, Hg2+ is bonded in a 5-coordinate geometry to five S2- atoms. There are a spread of Hg–S bond distances ranging from 2.36–3.46 Å. In the second Hg2+ site, Hg2+ is bonded in a 2-coordinate geometry to four S2- atoms. There are two shorter (2.36 Å) and two longer (3.28 Å) Hg–S bond lengths. In the third Hg2+ site, Hg2+ is bonded in a 5-coordinate geometry to five S2- atoms. There are a spread of Hg–S bond distances ranging from 2.35–3.33 Å. There are eighteen inequivalent S2- sites. In the first S2- site, S2- is bonded in a 5-coordinate geometry to four equivalent Ba2+ and one U+4.67+ atom. In the second S2- site, S2- is bonded in a 5-coordinate geometry to four Ba2+ and one U+4.67+ atom. In the third S2- site, S2- is bonded in a 6-coordinate geometry to two Ba2+, two equivalent U+4.67+, and two equivalent Hg2+ atoms. In the fourth S2- site, S2- is bonded in a distorted water-like geometry to three Ba2+ and two equivalent U+4.67+ atoms. In the fifth S2- site, S2- is bonded in a 1-coordinate geometry to four Ba2+ and one U+4.67+ atom. In the sixth S2- site, S2- is bonded in a 5-coordinate geometry to four equivalent Ba2+ and one U+4.67+ atom. In the seventh S2- site, S2- is bonded in a 6-coordinate geometry to two Ba2+, two equivalent U+4.67+, and two equivalent Hg2+ atoms. In the eighth S2- site, S2- is bonded in a 5-coordinate geometry to three Ba2+ and two equivalent U+4.67+ atoms. In the ninth S2- site, S2- is bonded in a 5-coordinate geometry to four Ba2+, one U+4.67+, and one Hg2+ atom. In the tenth S2- site, S2- is bonded in a 5-coordinate geometry to four equivalent Ba2+ and one U+4.67+ atom. In the eleventh S2- site, S2- is bonded in a 4-coordinate geometry to two Ba2+ and two equivalent U+4.67+ atoms. In the twelfth S2- site, S2- is bonded in a 6-coordinate geometry to two Ba2+, two equivalent U+4.67+, and two equivalent Hg2+ atoms. In the thirteenth S2- site, S2- is bonded to four Ba2+ and one Hg2+ atom to form a mixture of distorted edge and corner-sharing SBa4Hg square pyramids. In the fourteenth S2- site, S2- is bonded in a 6-coordinate geometry to four Ba2+ and two Hg2+ atoms. In the fifteenth S2- site, S2- is bonded to four Ba2+ and one Hg2+ atom to form a mixture of distorted edge and corner-sharing SBa4Hg square pyramids. In the sixteenth S2- site, S2- is bonded to four Ba2+ and one Hg2+ atom to form a mixture of distorted edge and corner-sharing SBa4Hg square pyramids. In the seventeenth S2- site, S2- is bonded to four Ba2+ and one Hg2+ atom to form a mixture of distorted edge and corner-sharing SBa4Hg square pyramids. In the eighteenth S2- site, S2- is bonded to four Ba2+ and one Hg2+ atom to form a mixture of distorted edge and corner-sharing SBa4Hg square pyramids.

Explore related subjects

Keep this discovery

Explore connections, maps & timelines

BibTeXRIS

2020-04-29. Materials Data on Ba8U3(HgS6)3 by Materials Project. https://doi.org/10.17188/1720438

Cite the original work for its findings. Save a collection to share your selection of sources.

KEEP EXPLORING

Related reports

Cyclic moisture reactivation of calcium sorbents for long duration thermochemical energy storage

The transition to a flexible and reliable energy infrastructure, using electro-thermal energy generation technologies such as geothermal, concentrated solar power, and nuclear, usually demands simultaneous advancement of thermal energy storage (TES) to support on-demand electricity generation and industrial applications while mitigating the inherent intermittency of renewable energy sources and power outages from direct energy generation. Among TES technologies, thermochemical energy storage (TCES) based on calcium looping emerges as a compelling high-power energy storage candidate due to its high reaction enthalpy, compatibility with elevated operating temperatures, and abundance of low-cost materials. However, the long-term durability of calcium-based sorbents for TCES is hindered by surface sintering and particle aggregation, leading to performance degradation over repeated thermal cycles. This study explores a moisture hydration-based strategy to regenerate a degraded calcium sorbent and mitigate performance degradation for long duration TCES. The addition of moisture transforms calcium oxide into calcium hydroxide and produces intercalation water layers, associated with a regenerated surface area and reduced calcium oxide crystallite size. Both these effects are beneficial in restoring the sorbents' reactivity for carbonization. Additionally, an optimized hydration-assisted reactivation protocol balances the recovered energy storage capacity with heating penalty required for moisture removal from hydrated samples, resulting in an enhanced energy storage capacity up to 176% compared to benchmark sorbents that undergo cycling without reactivation after 60 cycles. In conclusion, these results highlight the potential of hydration-assisted reactivation to enhance the long-term performance of TCES, providing an effective pathway to advancing electro-thermal storage technologies.

36 MATERIALS SCIENCE↗