Parameter variation in low-quartz between 94 and 298K

Page, Y. Le; Calvert, L. D.; Gabe, E. J.

doi:10.1016/0022-3697(80)90078-5

Cited by 120 publications

(43 citation statements)

References 7 publications

Supporting

Mentioning

Contrasting

Order By: Relevance

“…39 Lennard-Jones values identical to those for the SPC oxygen atom 30 were assigned to all oxygen atoms comprising the mineral lattice while partial charges were derived from electronic structure calculations for the simple oxides and hydroxides. Initially, the observed room-temperature structures for quartz (R-SiO 2 ), 40 corundum (R-Al 2 O 3 ), 41 boehmite (γ-AlO-(OH)), 42 diaspore (R-AlO(OH)), 43 and gibbsite (γ-Al(OH) 3 ) 44 were used to derive the optimum Si-O and octahedral Al-O interaction values. The structure of kaolinite (Al 2 Si 2 O 5 (OH) 4 ) derived by Bish 2 was later added to improve the number of observables to assist in the optimization of the Si-O interaction parameters.…”

Section: Methodsmentioning

confidence: 99%

Molecular Models of Hydroxide, Oxyhydroxide, and Clay Phases and the Development of a General Force Field

2004

View full text Add to dashboard Cite

The fate of chemical and radioactive wastes in the environment is related to the ability of natural phases to attenuate and immobilize contaminants through chemical sorption and precipitation processes. Our understanding of these complex processes at the atomic level is provided by a few experimental and analytical methods such as X-ray absorption and NMR spectroscopies. However, due to complexities in the structure and composition of clay and other hydrated minerals, and the inherent uncertainties of the experimental methods, it is important to apply theoretical molecular models for a fundamental atomic-level understanding, interpretation, and prediction of these phenomena. In this effort, we have developed a general force field, CLAYFF, suitable for the simulation of hydrated and multicomponent mineral systems and their interfaces with aqueous solutions. Interatomic potentials were derived from parametrizations incorporating structural and spectroscopic data for a variety of simple hydrated compounds. A flexible SPC-based water model is used to describe the water and hydroxyl behavior. Metal-oxygen interactions are described by a LennardJones function and a Coulombic term with partial charges derived by Mulliken and ESP analysis of DFT results. Bulk structures, relaxed surface structures, and intercalation processes are evaluated and compared to experimental and spectroscopic findings for validation. Our approach differs from most others in that we treat most interatomic interactions as nonbonded. This allows us to effectively use the force field for a wide variety of phases and to properly account for energy and momentum transfer between the fluid phase and the solid, while keeping the number of parameters small enough to allow modeling of relatively large and highly disordered systems. Simulations of clay, hydroxide, and oxyhydroxide phases and their interfaces with aqueous solutions combine energy minimization and molecular dynamics methods to describe the structure and behavior of water, hydroxyl, surface species, and intercalates in these systems. The results obtained to date demonstrate that CLAYFF shows good promise to evolve into a widely adaptable and broadly effective force field for molecular simulations of fluid interfaces with clays and other clay-related phases, as well as other inorganic materials characterized by complex, disordered, and often ill-determined structure and composition.

show abstract

Section: Methodsmentioning

confidence: 99%

Molecular Models of Hydroxide, Oxyhydroxide, and Clay Phases and the Development of a General Force Field

2004

View full text Add to dashboard Cite

show abstract

“…In Fig. 7, we report data for Ͱ-quartz from (33,35) and (32) at low and high temperature, respectively. The variations are limited by the Ͱ-ͱ structure transition at 846 K. In this range, we observe that the intrachain angle remains constant while the interchain angles are more sensitive to temperature since they are larger.…”

Section: When the (A) Temperature Effectmentioning

confidence: 96%

A General Survey of Quartz and Quartz-like Materials: Packing Distortions, Temperature, and Pressure Effects

Philippot

Palmier

Pintard

et al. 1996

Journal of Solid State Chemistry

View full text Add to dashboard Cite

“…Le Page, Calvert & Gabe (1980) showed that the slightly distorted SiO4 tetrahedron remains virtually rigid on heating from 94 to 298 K, with a rotation over this range of ,-,0.8 ° as the Si-O-Si angle between cornerlinked tetrahedra increases by ,,~ 1.0 °. The distortion from tetrahedral regularity is small, with the two independent Si-O bond lengths in each of the three tetrahedra per unit cell differing only by 0.005 ]k and the Si atom displaced only by 0.002 (1)/~ from the mass center of its four bonded O atoms.…”

Section: Piezoelectric Hexagonal A-quartzmentioning

confidence: 99%

Structure relationship to dielectric, elastic and chiral properties

Abrahams¹

1994

Acta Cryst Sect A

View full text Add to dashboard Cite

Crystallography provides a major approach toward reaching an understanding of the relationship between crystal structure and material physical properties. The specific relationships of five highly structure dependent physical properties, namely piezoelectricity, pyroelectricity, ferroelectricity, ferroelasticity and optical activity, to atomic arrangement are developed in this Lead Article. The major attributes of each property, together with the structural measurements required to establish the property-structure relationship, are introduced and illustrative results for each are given. Predictive criteria that emphasize the insight leading to new property-structure relationships are presented as is an expanded experimental access to the crystallographic study of materials.

show abstract

Parameter variation in low-quartz between 94 and 298K

Cited by 120 publications

References 7 publications

Molecular Models of Hydroxide, Oxyhydroxide, and Clay Phases and the Development of a General Force Field

Molecular Models of Hydroxide, Oxyhydroxide, and Clay Phases and the Development of a General Force Field

A General Survey of Quartz and Quartz-like Materials: Packing Distortions, Temperature, and Pressure Effects

Structure relationship to dielectric, elastic and chiral properties

Contact Info

Product

Resources

About