Theory of ice structures

Dmitriev, Vladimir; Rochal, S.B.; Tolédano, Pierre

doi:10.1103/physrevlett.71.553

Cited by 16 publications

(6 citation statements)

References 20 publications

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“…Water confined in nanospaces exhibits complex and incompletely understood phase behavior and physical properties that can be quite different than those of bulk liquid water and crystalline ice. − The effects of water confinement play important roles in many chemical, geological, and biological processes, such as hydration and reactivity of mineral surfaces in natural environments, hydrophobic interactions of peptides and lipid membranes, and the stability of tissues below the point of ice crystallization due to freezing point depression in the vicinity of macromolecules and membranes. − In recent years, these effects have been extensively studied experimentally ,, and computationally. − The confinement-induced changes in the water structure and dynamics are commonly substrate-specific because the substrate−water interaction spatially restricts the translational and rotational mobility of individual H 2 O molecules and may also cause significant water−substrate hydrogen bonding. For instance, neutron scattering studies have shown that water in silica pores can freeze to cubic ice, Ic, instead of hexagonal ice, Ih, , and a two-dimensional (2-D) ice with rings of eight water molecules forms in a layered nickel chelate complex .…”

Section: Introductionmentioning

confidence: 99%

Structure and Decompression Melting of a Novel, High-Pressure Nanoconfined 2-D Ice

2005

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Molecular dynamics (MD) simulations of water confined in nanospaces between layers of talc (system composition Mg(3)Si(4)O(10)(OH)(2) + 2H(2)O) at 300 K and pressures of approximately 0.45 GPa show the presence of a novel 2-D ice structure, and the simulation results at lower pressures provide insight into the mechanisms of its decompression melting. Talc is hydrophobic at ambient pressure and temperature, but weak hydrogen bonding between the talc surface and the water molecules plays an important role in stabilizing the hydrated structure at high pressure. The simulation results suggest that experimentally accessible elevated pressures may cause formation of a wide range of previously unknown water structures in nanoconfinement. In the talc 2-D ice, each water molecule is coordinated by six O(b) atoms of one basal siloxane sheet and three water molecules. The water molecules are arranged in a buckled hexagonal array in the a-b crystallographic plane with two sublayers along [001]. Each H(2)O molecule has four H-bonds, accepting one from the talc OH group and one from another water molecule and donating one to an O(b) and one to another water molecule. In plan view, the molecules are arranged in six-member rings reflecting the substrate talc structure. Decompression melting occurs by migration of water molecules to interstitial sites in the centers of six-member rings and eventual formation of separate empty and water-filled regions.

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Section: Introductionmentioning

confidence: 99%

Structure and Decompression Melting of a Novel, High-Pressure Nanoconfined 2-D Ice

2005

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“…28 Theoretical efforts include calculations of the electronic, bulk, and surface structures of ice. 15,[29][30][31] Many reviews of the general properties of water, ice, and ice films are in the literature. 6,7,32 Despite the tremendous amount of work per-formed in this field, the nature of the ice surface is still a topic of active investigation.…”

Section: Introductionmentioning

confidence: 99%

Electron-stimulated desorption of D+from D2O ice: Surface structure and electronic excitations

1997

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We present a study of the electron-stimulated desorption of deuterium cations ͑D ϩ) from thin ͑1-40 ML͒ D 2 O ice films vapor deposited on a Pt͑111͒ substrate. Measurements of the total yield and velocity distributions as a function of temperature from 90 to 200 K show that the D ϩ yield changes with film thickness, surface temperature, and ice phase. We observe two energy thresholds for cation emission, near 25 and 40 eV, which are weakly dependent upon the ice temperature and phase. The cation time-of-flight ͑TOF͒ distribution is at least bimodal, indicating multiple desorption channels. A decomposition of the TOF distributions into ''fast'' and ''slow'' channels shows structure as a function of excitation energy, film thickness, and temperature. The D ϩ yield generally increases with temperature, rising near 120 K on amorphous ice, and near 135 K on crystalline ice. The amorphous-crystalline phase transition at ϳ160 K causes a drop in total desorption yield. The temperature dependence of D Ϫ desorption via the 2 B 1 dissociative electron attachment resonance is very similar to the slow D ϩ yield, and likely involves similar restructuring and lifetime effects. The data collectively suggest that a thermally activated reduction of surface hydrogen bonding increases the lifetime of the excited states responsible for ion desorption, and that these lifetime effects are strongest for excited states involving a 1 bands ͓S0163-1829͑97͒05931-6͔

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“…In the gas phase, its rovibrational spectrum is well known up to 26000 cm -1 [1][2][3] and in the solid state, the structures of the different forms of ice have been extensively studied [4][5][6]. Ice grains play an important role in the chemistry of the interstellar medium and of planetary atmospheres [7,8].…”

Section: Introductionmentioning

confidence: 99%

The vibration–rotation of H2O and its complexation with CO2 in solid argon revisited

Michaut

Vasserot

Abouaf‐Marguin

2003

Low Temperature Physics

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Fourier-transform infrared spectroscopy in the frequency range 400-4000 cm -1 has been used to investigate the absorption of H 2 O and H 2 O:CO 2 complex isolated in solid argon. Thanks to the lowest temperature reached in our experiment, temperature effects and nuclear spin conversion studies allow us to propose a new assignment of the rovibrational lines in the bending band n 2 for the quasi-freely rotating H 2 O. An additional wide structure observed in this band shows two maxima around 1657.4 and 1661.3 cm -1 , with nuclear spin conversion of the high frequency part into the low frequency one. This structure is tentatively attributed to a rotation-translation coupling of the molecule in the cage. However, the equivalent effect is not observed in the vibrational stretching bands n 1 and n 3 . Finally, by double doping experiments with CO 2 , important new structures appear, leading us to unambiguously extract the frequencies of the lines of the H 2 O:CO 2 complex.

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Theory of ice structures

Abstract: The structures of nine phases of ice are described as the result of ordering and displacive mechanisms from a common parent disordered body centered cubic structure possessing different fractional concentrations of water molecules.

Cited by 16 publications

References 20 publications

Structure and Decompression Melting of a Novel, High-Pressure Nanoconfined 2-D Ice

Structure and Decompression Melting of a Novel, High-Pressure Nanoconfined 2-D Ice

Electron-stimulated desorption of D+from D2O ice: Surface structure and electronic excitations

The vibration–rotation of H2O and its complexation with CO2 in solid argon revisited

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