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Depositordc.contributorHermann, Andreas
Funderdc.contributor.otherEPSRC - Engineering and Physical Sciences Research Councilen_UK
Funderdc.contributor.otherThe Royal Societyen_UK
Data Creatordc.creatorHermann, Andreas
Data Creatordc.creatorNaden-Robinson, Victor
Date Accessioneddc.date.accessioned2017-07-26T15:48:51Z
Date Availabledc.date.available2017-08-08T04:15:22Z
Citationdc.identifier.citationHermann, Andreas; Naden-Robinson, Victor. (2017). Stabilization of ammonia-rich hydrate inside icy planets, [dataset]. University of Edinburgh. School of Physics and Astronomy. Institute of Condensed Matter and Complex Systems. https://doi.org/10.7488/ds/2104.en
Persistent Identifierdc.identifier.urihttp://hdl.handle.net/10283/2777
Persistent Identifierdc.identifier.urihttps://doi.org/10.7488/ds/2104
Dataset Description (abstract)dc.description.abstractThe interior structure of the giant ice planets Uranus and Neptune, but also of newly discovered exoplanets, is loosely constrained, because limited observational data can be satisfied with various interior models. Although it is known that their mantles comprise large amounts of water, ammonia, and methane ices, it is unclear how these organize themselves within the planets -- as homogeneous mixtures, with continuous concentration gradients, or as well-separated layers of specific composition. While individual ices have been studied very detailed under pressure, the properties of their mixtures are much less explored. We show here, using first-principles calculations, that the 2:1 ammonia hydrate, (H2O)(NH3)2, is stabilized at icy planet mantle conditions due to a remarkable structural evolution. Above 65 GPa, we predict it to transform from a hydrogen-bonded molecular solid into a fully ionic phase O2-(NH4+)2, where all water molecules are completely deprotonated, an unexpected bonding phenomenon not seen before. Ammonia hemihydrate is stable in a sequence of ionic phases up to 500 GPa, pressures found deep within Neptune-like planets, and thus at higher pressures than any other ammonia-water mixture. This suggests it precipitates out of any ammonia-water mixture at sufficiently high pressures and thus forms an important component of icy planets.en_UK
Dataset Description (TOC)dc.description.tableofcontentsSee Readme file.en_UK
Languagedc.language.isoengen_UK
Publisherdc.publisherUniversity of Edinburgh. School of Physics and Astronomy. Institute of Condensed Matter and Complex Systemsen_UK
Relation (Is Referenced By)dc.relation.isreferencedbyhttps://doi.org/10.1073/pnas.1706244114en_UK
Rightsdc.rightsCreative Commons Attribution 4.0 International Public Licenseen
Subjectdc.subjectammonia hydrateen_UK
Subjectdc.subjectpressureen_UK
Subjectdc.subjectdensity functional theoryen_UK
Subjectdc.subjectphase transitionsen_UK
Subject Classificationdc.subject.classificationPhysical Sciences::Computational Physicsen_UK
Titledc.titleStabilization of ammonia-rich hydrate inside icy planetsen_UK
Typedc.typedataseten_UK

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