Molecular structural order and anomalies in liquid silica.

@article{Shell2002MolecularSO,
  title={Molecular structural order and anomalies in liquid silica.},
  author={M. Scott Shell and Pablo G. Debenedetti and Athanassios Z. Panagiotopoulos},
  journal={Physical review. E, Statistical, nonlinear, and soft matter physics},
  year={2002},
  volume={66 1 Pt 1},
  pages={
          011202
        }
}
The present investigation examines the relationship between structural order, diffusivity anomalies, and density anomalies in liquid silica by means of molecular dynamics simulations. We use previously defined orientational and translational order parameters to quantify local structural order in atomic configurations. Extensive simulations are performed at different state points to measure structural order, diffusivity, and thermodynamic properties. It is found that silica shares many trends… 

Figures from this paper

Nesting of thermodynamic, structural, and dynamic anomalies in liquid silicon.

TLDR
Excess entropy based criteria for diffusivity and structural anomalies fail to capture the observed regions of anomaly, and scaling relations associating the excess entropy with the diffusion coefficient show considerable deviation from the quasi-universal behaviour observed in hard-sphere and Lennard-Jones liquids and some liquid metals.

Entropy, diffusivity, and structural order in liquids with waterlike anomalies.

TLDR
Within the category of liquids with waterlike anomalies, it is shown that the relationship between the macroscopic entropy and internal energy is sufficient to distinguish between those with local anisotropy and consequent open packings at low densities and those with isotropic interactions but multiple length scales.

Structural, vibrational, and thermal properties of densified silicates: insights from molecular dynamics.

  • M. Bauchy
  • Physics
    The Journal of chemical physics
  • 2012
TLDR
It is shown that the thermal behavior of the liquid can be reproduced by the Birch-Murnaghan equation of states, thus allowing us to compute the isothermal compressibility.

Relationship between structural order and water-like anomalies in metastable liquid silicon: Ab initio molecular dynamics

TLDR
First-principle molecular dynamics are performed to study the relationship between structural order and water-like anomalies in tetrahedral liquids in metastable liquid Si and it is found that in T-P phase diagram, there indeed exists a structural anomaly region, which encloses density anomaly but not diffusivity anomaly.

Fragile-to-strong transition in liquid silica

We investigate anomalies in liquid silica with molecular dynamics simulations and present evidence for a fragile-to-strong transition at around 3100 K-3300 K. To this purpose, we studied the

Molecular Dynamics Simulations of Liquid Phosphorus at High Temperature and Pressure

By performing ab initio molecular dynamics simulations, we have investigated the microstructure, dynamical and electronic properties of liquid phosphorus (P) under high temperature and pressure. In

Pressure-induced structural and dynamic transitions in stimulated liquid aluminosilicate nanoparticles

We have investigated the pressure-induced structural and dynamic transitions in liquid aluminosilicate (Al2O32SiO2) nanoparticles with a molecular dynamics (MD) method. Simulations were performed in

Fluctuations near the liquid-liquid transition in a model of silica.

TLDR
Large-scale molecular dynamics simulations of systems with up to 216 000 atoms are performed to study the low-temperature behavior of the mWAC model of silica, revealing an anomalous increase in fluctuations in density and local tetrahedral order in the liquid upon cooling.

How short-range attractions impact the structural order, self-diffusivity, and viscosity of a fluid.

TLDR
Simulation data suggest how repulsive and attractive glasses may generally be characterized by two distinct levels of short-range structural order, and how these couplings reflect dynamic heterogeneities.
...

References

SHOWING 1-10 OF 92 REFERENCES

Relationship between structural order and the anomalies of liquid water

TLDR
This work identifies a structurally anomalous region that encloses the entire range of temperatures and densities for which the anomalous diffusivity and thermal expansion coefficient of water are observed, and enables us to quantify the degree of structural order needed for these anomalies to occur.

Towards a quantification of disorder in materials: distinguishing equilibrium and glassy sphere packings

TLDR
This investigation provides fresh insights into the types of ordering that can occur in equilibrium and glassy systems, including quantitative evidence that contradicts the notion that glasses are simply solids with the "frozen in" structure of an equilibrium liquid.

Static and dynamic properties of a viscous silica melt

We present the results of a large scale molecular dynamics computer simulation in which we investigated the static and dynamic properties of a silica melt in the temperature range in which the

Configurational entropy and diffusivity of supercooled water

TLDR
It is found that the thermodynamic approach can be used to understand the characteristic dynamic anomalies of liquid water, and that the diffusive dynamics are governed by the configurational entropy.

Instantaneous normal modes analysis of amorphous and supercooled silica

The dynamics of a model for amorphous and supercooled silica (SiO2), a strong glass former, is studied using instantaneous normal mode (INM) analysis. The INM spectra at a variety of temperatures are

A numerical investigation of the liquid–vapor coexistence curve of silica

In using a modified version of the interionic potential of Tsuneyuki, Tsukada, Aoki, and Matsui [Phys. Rev. Lett. 61, 869 (1988)] for silica we have evaluated by molecular dynamics simulation the

Water and its anomalies in perspective: Tetrahedral liquids with and without liquid-liquid phase transitions

We show how water with its small proton bridge between tetrahedrally coordinated oxygen centers, forms a provocative series with (i) the archetypal glassformer and strong liquid, SiO2, (ii) the

Fragile-to-strong transition and polyamorphism in the energy landscape of liquid silica

TLDR
The results reveal a change in the energy landscape with decreasing temperature, which underlies a transition from a fragile liquid at high temperature to a strong liquid at low temperature, and it is suggested that a specific heat anomaly is associated with this fragile-to-strong transition.

Thermodynamic determination of fragility in liquids and a fragile-to-strong liquid transition in water

If crystallization can be avoided when a liquid is cooled, it will typically form a glass. Near the glass transition temperature the viscosity increases continuously but rapidly with cooling. As the
...