Nearest neighbor assessments of spatial distribution in CO2: A molecular dynamics analysis

Idrissi, A.; Damay, P.; Киселев, М. Г.

doi:10.1016/j.chemphys.2006.11.037

Cited by 29 publications

(28 citation statements)

References 21 publications

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“…The DZ (Zhang & Duan, 2005;Duan & Zhang, 2006;Idrissi et al, 2007) and EPM2 (Harris & Yung, 1995;da Rocha & Johnston, 2001;Tegze et al, 2006;Nieto-Draghi et al, 2007;Kvamme et al, 2007) CO 2 model LJ parameters are nearly identical (Figure 2), but the DZ model assigns considerably smaller partial charges to C and O atoms ( interactions have larger ε and slightly larger σ than the others (Table 1) and the partial charges on CO 2 fall between those of the EPM2 and DZ models.…”

Section: Force Field Selectionmentioning

confidence: 90%

Predicting CO2–water interfacial tension under pressure and temperature conditions of geologic CO2 storage

Nielsen

Bourg

Sposito

2012

Geochimica et Cosmochimica Acta

135

172

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Storage in subsurface geologic formations, principally saline aquifers, is currently under development as a major approach to counter anthropogenic CO 2 emissions. To ensure the stability and long-term viability of geologic carbon storage, injected CO 2 must be kept in place by an overlying cap rock of very low permeability. Capillary forces in the cap rock act to prevent upward migration and escape of the stored supercritical fluid, with interfacial tension (IFT) between the aqueous brine phase and the CO 2 phase being the primary control. However, published experimental CO 2 -water IFT data vary widely, mainly because of inadequate experimental protocols or inappropriate use of bulk-fluid properties in computing IFT from experimental observations. Only two published data sets were found to meet all criteria of merit for an accurate measurement of IFT over the entire range of pressure (5-45 MPa) and temperature (298-383 K) pertinent to geologic carbon storage. In such circumstances, molecular simulations can enhance the utility of limited data when used to validate assumptions made in their interpretation, resolve discrepancies among data, and fill gaps where data are lacking. Simulations may also be used to provide insight into the relationship between IFT and fundamental properties, such as the strength of the CO 2 -H 2 O interaction. Through molecular dynamics simulations, we compared the quality of three CO 2 models and two H 2 O models (SPC/E and TIP4P2005) in predicting IFT under the pressure and temperature conditions relevant to geologic CO 2 sequestration. Interfacial tension at fixed temperature simulated via molecular dynamics decreased strongly with increasing pressure below the critical CO 2 pressure of 7 MPa, then leveled off, in agreement with experiment, whereas increasing temperature from 300 to 383 K at fixed pressure had little effect on IFT, which is also

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Section: Force Field Selectionmentioning

confidence: 90%

Predicting CO2–water interfacial tension under pressure and temperature conditions of geologic CO2 storage

Nielsen

Bourg

Sposito

2012

Geochimica et Cosmochimica Acta

135

172

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“…Taking into account that by definition the tetrahedral and trigonal order parameters depend upon the distribution of nearest neighbors, this signifies that the closest three and four neighbors of each individual water molecule are distributed over a more extended length scale of the first and second solvation shell, which are located at 4.22 and 6.75 Å, respectively at the bulk density of 2.0 c  .In order to provide a deeper description of these effects, the distribution of nearest neighbors and their contribution on the overall shape of the O-O rdfs obtained were systematically explored by employing a methodology similar to the one used in recent studies[64,65]. The nearest neighbors have been classified by sorting their distances from a central molecule.…”

mentioning

confidence: 99%

Local structural fluctuations, hydrogen bonding and structural transitions in supercritical water

Skarmoutsos

Guàrdia

Samios

2017

The Journal of Supercritical Fluids

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The contribution of hydrogen bonding interactions to the formation of local density inhomogeneities in supercritical water at near-critical conditions has been extensively studied by means of molecular dynamics simulations. The results obtained have revealed the strong effect of water molecules forming one and two hydrogen bonds on the determination of the local density augmentation in the fluid. The local structural order has also been studied in terms of the trigonal and tetrahedral order parameters, revealing the correlation between local orientational order and hydrogen bonding. The dynamics of the structural order parameters exhibit similarities with local density ones. The local structural analysis performed in terms of nearest neighbors around the individual molecules provides additional significant evidence about the existence of a liquid-like to gas-like structural transition in supercritical water at the density range close to 0.2 ¿c, further supporting previous suggestions based on the interpretation of experimental thermodynamic data.Postprint (author's final draft

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“…of the first coordination shell is not only specific for water, but it also occurs for monoatomic systems, such as Ar, 46 as well as for systems of apolar molecules, such as CO 2 . 44 Both ∆r O W . .…”

Section: When a Linear Hydrogen Bond Occurs Between O W • • • X The mentioning

confidence: 99%

“…The distributions are defined in an unambiguous way, allowing the characterization of the local structure. The two approaches are well documented in our previous papers, 36,38,[44][45][46] therefore, we only summarize here the most important details, while the description of the last one will be given later. For a given distribution of a set of molecules, the VP of the central molecule is the region of space closer to this molecule than to any other one.…”

Section: Statistical Functionsmentioning

confidence: 99%

Local structure of dilute aqueous DMSO solutions, as seen from molecular dynamics simulations

Idrissi

Marekha

Barj

et al. 2017

The Journal of Chemical Physics

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The information about the structure of dimethyl sulfoxide (DMSO)-water mixtures at relatively low DMSO mole fractions is an important step in order to understand their cryoprotective properties as well as the solvation process of proteins and amino acids. Classical MD simulations, using the potential model combination that best reproduces the free energy of mixing of these compounds, are used to analyze the local structure of DMSO-water mixtures at DMSO mole fractions below 0.2. Significant changes in the local structure of DMSO are observed around the DMSO mole fraction of 0.1. The array of evidence, based on the cluster and the metric and topological parameters of the Voronoi polyhedra distributions, indicates that these changes are associated with the simultaneous increase of the number of DMSO-water and decrease of water-water hydrogen bonds with increasing DMSO concentration. The inversion between the dominance of these two types of H-bonds occurs around X = 0.1, above which the DMSO-DMSO interactions also start playing an important role. In other words, below the DMSO mole fraction of 0.1, DMSO molecules are mainly solvated by water molecules, while above it, their solvation shell consists of a mixture of water and DMSO. The trigonal, tetrahedral, and trigonal bipyramidal distributions of water shift to lower corresponding order parameter values indicating the loosening of these orientations. Adding DMSO does not affect the hydrogen bonding between a reference water molecule and its first neighbor hydrogen bonded water molecules, while it increases the bent hydrogen bond geometry involving the second ones. The close-packed local structure of the third, fourth, and fifth water neighbors also is reinforced. In accordance with previous theoretical and experimental data, the hydrogen bonding between water and the first, the second, and the third DMSO neighbors is stronger than that with its corresponding water neighbors. At a given DMSO mole fraction, the behavior of the intensity of the high orientational order parameter values indicates that water molecules are more ordered in the vicinity of the hydrophilic group while their structure is close-packed near the hydrophobic group of DMSO.

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Nearest neighbor assessments of spatial distribution in CO2: A molecular dynamics analysis

Cited by 29 publications

References 21 publications

Predicting CO2–water interfacial tension under pressure and temperature conditions of geologic CO2 storage

Predicting CO2–water interfacial tension under pressure and temperature conditions of geologic CO2 storage

Local structural fluctuations, hydrogen bonding and structural transitions in supercritical water

Local structure of dilute aqueous DMSO solutions, as seen from molecular dynamics simulations

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