High pressure partially ionic phase of water ice

Wang, Yanchao; Liu, Hanyu; Lv, Jian; Zhu, Li; Wang, Hui

doi:10.1038/ncomms1566

Cited by 215 publications

(110 citation statements)

References 32 publications

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“…There is another possibility that also merits further examination, namely that because of the possible onset of H (or D) diffusion, high pressure ices may adopt fluid states. After our work was completed, we became aware of several new studies of high pressure ice phases (44)(45)(46). The structures obtained in these studies mostly agree with ours.…”

Section: Discussionsupporting

confidence: 69%

High pressure ices

Hermann

Ashcroft

Hoffmann

2011

Proc. Natl. Acad. Sci. U.S.A.

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H 2 O will be more resistant to metallization than previously thought. From computational evolutionary structure searches, we find a sequence of new stable and meta-stable structures for the ground state of ice in the 1-5 TPa (10 to 50 Mbar) regime, in the static approximation. The previously proposed Pbcm structure is superseded by a Pmc2 1 phase at p ¼ 930 GPa, followed by a predicted transition to a P2 1 crystal structure at p ¼ 1.3 TPa. This phase, featuring higher coordination at O and H, is stable over a wide pressure range, reaching 4.8 TPa. We analyze carefully the geometrical changes in the calculated structures, especially the buckling at the H in O-H-O motifs. All structures are insulatingchemistry burns a deep and (with pressure increase) lasting hole in the density of states near the highest occupied electronic levels of what might be component metallic lattices. Metallization of ice in our calculations occurs only near 4.8 TPa, where the metallic C2∕m phase becomes most stable. In this regime, zero-point energies much larger than typical enthalpy differences suggest possible melting of the H sublattice, or even the entire crystal.hydrogen bonds | compressed water

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Section: Discussionsupporting

confidence: 69%

High pressure ices

Hermann

Ashcroft

Hoffmann

2011

Proc. Natl. Acad. Sci. U.S.A.

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“…Note that recent work 5 has suggested a different, more complicated structure of I -4 2 d symmetry as a more stable intermediate phase between the Pbcm and the P 2 1 structures. Other recent work has predicted yet other more stable structures in the terapascal pressure regime 32,33 ; however, we believe the structural features of these high-pressure phases to be sufficiently similar to allow us to draw conclusions from a detailed study of the phases discussed in this paper.…”

Section: Stable Phase Boundaries and The Isotope Effectmentioning

confidence: 99%

“…1 Recent studies on stable high pressure phases of ice have uncovered a variety of new phases that become stable at pressures beyond P = 1 TPa (1000 GPa, or 10 Mbar). [2][3][4][5][6] There is now an understanding that the electronic band gap of ice is not likely to close until pressures reach around P = 5 TPa (corresponding to a compression of roughly V 0 /V = 11.5), where metallic ice phases actually first become more stable than all known insulating phases. The stable ice phases at these pressures are notably more complex than, e.g., the highly symmetric phase ice X, which becomes stable around P = 100 GPa and which features symmetric and linear O-H-O bridging bonds.…”

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confidence: 99%

Isotopic differentiation and sublattice melting in dense dynamic ice

2013

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The isotopes of hydrogen provide a unique exploratory laboratory for examining the role of zero point energy (ZPE) in determining the structural and dynamic features of the crystalline ices of water. There are two critical regions of high pressure: (i) near 1 TPa and (ii) near the predicted onset of metallization at around 5 TPa. At the lower pressure of the two, we see the expected small isotopic effects on phase transitions. Near metallization, however, the effects are much greater, leading to a situation where tritiated ice could skip almost entirely a phase available to the other isotopomers. For the higher pressure ices, we investigate in some detail the enthalpics of a dynamic proton sublattice, with the corresponding structures being quite ionic. The resistance toward diffusion of single protons in the ground state structures of high-pressure H 2 O is found to be large, in fact to the point that the ZPE reservoir cannot overcome these. However, the barriers toward a three-dimensional coherent or concerted motion of protons can be much lower, and the ensuing consequences are explored.

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“…By only using chemical component information, these authors have been successful in determining stable configurations of O 4 , Li, and ice under high pressure [17][18][19]. We refer to our search algorithm as partial particle swarm optimization (PPSO) method.…”

Section: Introductionmentioning

confidence: 99%

Tailoring Li adsorption on graphene

et al. 2014

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The technological potential of functionalized graphene has recently stimulated considerable interest in the study of the adsorption of metal atoms on graphene. However, a complete understanding of the optimal adsorption pattern of metal atoms on a graphene substrate has not been easy because of atomic relaxations at the interface and the interaction between metal atoms. We present a partial particle swarm optimization technique that allows us to efficiently search for the equilibrium geometries of metal atoms adsorbed on a substrate as a function of adatom concentration. Using Li deposition on graphene as an example we show that, contrary to previous works, Li atoms prefer to cluster, forming four-atom islands, irrespective of their concentration. We further show that an external electric field applied vertically to the graphene surface or doping with boron can prevent this clustering, leading to the homogeneous growth of Li.

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High pressure partially ionic phase of water ice

Cited by 215 publications

References 32 publications

High pressure ices

High pressure ices

Isotopic differentiation and sublattice melting in dense dynamic ice

Tailoring Li adsorption on graphene

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