Application of a New Three-Body Potential to Vitreous Silica and Sodium Silicate Glasses

1988 ◽  
Vol 141 ◽  
Author(s):  
B. P. Feuston ◽  
R. N. Newell ◽  
S. H. Garofalini
Keyword(s):  
Sodium Silicate ◽  
Silicate Glass ◽  
Md Simulations ◽  
Pair Interaction ◽  
Vitreous Silica ◽  
Static Structure Factor ◽  
Static Structure ◽  
Three Body ◽  
Body Potential ◽  
Good Agreement

AbstractAn empirical three-body potential, suitable for molecular dynamics (MD) simulations, has been developed to model the natural covalency of the Si-O bond in vitreous silica and silicate glass systems. Through the addition of a small directional-dependent three-body term to a previously used modified ionic pair interaction, a narrow distribution of tetrahedral angles and a low concentration of defects were obtained, in good agreement with experiment. The structure of bulk silica resulting from the MD technique also contained a larger average ring size, no edge-sharing tetrahedra, and a calculated static structure factor in good agreement with neutron diffraction results. The simulated sodium silicate glass was also largely improved over previous simulations using pair interactions alone. All silicon atoms were found to be exactly four coordinated while the number of non-bridging oxygen nearly equaled the number of sodium ions present with a reasonable distribution of Qi species.

Classical Molecular Dynamics Simulation of Structural and Dynamical Properties of II-VI and III-V Semiconductors

2006 ◽  
Vol 258-260 ◽  
pp. 522-530 ◽  
Author(s):  
José Pedro Rino ◽  
Paulo S. Branício ◽  
Denílson S. Borges
Keyword(s):  
Interaction Potential ◽  
Dipole Interaction ◽  
Van Der Waals Interactions ◽  
Dynamics Simulation ◽  
Static Structure Factor ◽  
Static Structure ◽  
Liquid Phases ◽  
Bond Stretching ◽  
Dynamical Properties ◽  
Three Body

An effective inter-atomic potential is proposed in order to describe structural and dynamical properties of II-VI and III-V semiconductors. The interaction potential consists of twoand three-body interactions. The two-body term takes into account steric repulsion, charge-induce dipole interaction due to the electronic polarizability of ions, Coulomb interaction due to charge transfer between ions, and dipole-dipole (van der Waals) interactions. The three-body term, which has a modified Stillinger-Weber form, describes bond-bending as well as bond-stretching effects. Here we report the fitting and the application of this interaction potential for InP in the crystalline phase and for CdTe in the crystalline and liquid phases. The structural correlations are discussed through pair distribution, coordination number and bond-angle functions. Vibrational density of states for InP and CdTe as well as the static structure factor for liquid CdTe are in very good agreement with experimental data.

Clustering and Extended Range Order in Binary Network Glasses

1995 ◽  
Vol 408 ◽  
Author(s):  
Dmitry Nekhayev ◽  
John Kieffer
Keyword(s):  
Network Structure ◽  
Pair Correlation ◽  
Range Order ◽  
Static Structure Factor ◽  
Static Structure ◽  
Silica Glasses ◽  
Dynamics Simulations ◽  
Binary Network ◽  
Three Body ◽  
Semi Empirical

AbstractThe clustering in alkali silica glasses (M2O) x (SiO2)1-x, where M is either Na or Rb, and x ranges between 0 and 0.4, was studied using molecular dynamics simulations. Computations were performed using a semi-empirical potential, including two- and three-body terms as well as dynamic partial charge transfer. Characterization of the structures was based on pair correlation functions, neutron static structure factor and ring statistics. Results have shown a much stronger tendency to cluster in case of Na than of Rb. The irregular arrangement of Na is evidenced by a decay pattern in the Na-Na pair correlation function, which can be associated with a fractal dimension. The clustering tendency can be attributed to the differences in the way the network structure is able to accommodate the introduction of modifying cations. As opposed to Rb, the smaller Na cation can fit on sites only slightly larger than is required for Si. This would distort the structure but hardly alter its topology. Rb on the other hand, requires larger interstices, which results in a reconstruction of the network and a significantly different intermediate range order. Na can achieve a similar influence on the network structure if they group in pairs.

Three-body potential modeling of undoped and Er3+-doped lead silicate glass

1997 ◽  
Vol 221 (1) ◽  
pp. 34-46 ◽  
Author(s):  
T. Peres ◽  
D.A. Litton ◽  
J.A. Capobianco ◽  
S.H. Garofalini
Keyword(s):  
Silicate Glass ◽  
Lead Silicate ◽  
Lead Silicate Glass ◽  
Three Body ◽  
Body Potential

scholarly journals Investigation of Structural Phase Transition of PbS

2012 ◽  
Vol 2012 ◽  
pp. 1-4 ◽  
Author(s):  
Purvee Bhardwaj
Keyword(s):  
Phase Transition ◽  
High Pressure ◽  
Elastic Properties ◽  
Structural Phase Transition ◽  
Structural Phase ◽  
Three Body ◽  
Body Potential ◽  
Model Phase ◽  
Sudden Collapse ◽  
Good Agreement

The high-pressure structural phase transition of semiconductor PbS has been investigated, using the three body potential (TBP) model. Phase transition pressures are associated with a sudden collapse in volume. The phase transition pressures and related volume collapses obtained from this model show a generally good agreement with available results. Moreover, the elastic properties of PbS are also investigated.

Thermodynamics and Kinetics of Melting and Growth of Crystalline Silicon Clusters

1998 ◽  
Vol 536 ◽  
Author(s):  
P. Keblinski
Keyword(s):  
Melting Temperature ◽  
Cluster Size ◽  
Crystalline Silicon ◽  
Md Simulations ◽  
Silicon Clusters ◽  
Homoepitaxial Growth ◽  
Thermodynamics And Kinetics ◽  
Three Body ◽  
Body Potential ◽  
Kinetics Of

AbstractMolecular-dynamics (MD) simulations and the Stillinger-Weber three-body potential are used to study the growth and stability of silicon clusters of diameters from 2 to 5 nm embedded in the melt. Our simulations show that the melting temperature of such nano-clusters is lower than the bulk melting temperature by an amount proportional to the inverse of the cluster size. We also show that the nature of the kinetics of such small Si clusters is essentially the same as that of the homoepitaxial growth. In particular, we show that the mobility of the highly-curved crystalliquid interface is controlled by diffusion in the adjacent melt, and is characterized by the same activation energy.

A lattice dynamical study of Cu and Ni based on a new empirical many-body potential

1995 ◽  
Vol 73 (3-4) ◽  
pp. 143-146 ◽  
Author(s):  
I. Akgün
Keyword(s):  
Potential Energy Function ◽  
Many Body ◽  
Dynamical Study ◽  
Dynamical Behaviors ◽  
Atomic Interactions ◽  
The Face ◽  
Experimental Values ◽  
Three Body ◽  
Body Potential ◽  
Good Agreement

In the present work, a recently developed empirical many-body potential-energy function (PEF) is first used, as an application, to investigate the dynamical behaviors of the face-centred-cube d-band metals, Cu and Ni. The new PEF contains both two- and three-body atomic interactions. The two-body potential is a kind of hybrid function and the three-body potential is expressed in terms of the two-body interactions. The parameters defining the PEF for the metals are computed following a procedure similar to a method given by Girifalco and Weizer. The input data for evaluating the necessary parameters are independent of the phonon frequencies and elastic constants of the metals. The phonon frequencies along the principal symmetry directions of Cu and Ni are calculated using the computed two- and three-body force constants. The results are found to be in good agreement with the corresponding experimental values.

Empirical three‐body potential for vitreous silica

1988 ◽  
Vol 89 (9) ◽  
pp. 5818-5824 ◽  
Author(s):  
B. P. Feuston ◽  
S. H. Garofalini
Keyword(s):  
Vitreous Silica ◽  
Three Body ◽  
Body Potential

scholarly journals Structural and Thermophysical Properties of Cadmium Oxide

2012 ◽  
Vol 2012 ◽  
pp. 1-4 ◽  
Author(s):  
Purvee Bhardwaj
Keyword(s):  
Phase Transition ◽  
Debye Temperature ◽  
Thermophysical Properties ◽  
Cadmium Oxide ◽  
Molecular Force ◽  
Three Body ◽  
Body Potential ◽  
Model Phase ◽  
Sudden Collapse ◽  
Good Agreement

We have studied the structural and thermophysical properties of cadmium oxide (CdO), using the Three-Body Potential (TBP) model. Phase transition pressures are associated with a sudden collapse in volume. The phase transition pressures and related volume collapses obtained from this model show a generally good agreement with available experimental others data. The thermophysical properties like molecular force constant, Debye temperature, and so forth, of CdO are also reported.

Molecular Dynamics Simulation of Mass and Charge Transport in Superionic Conductors, and Structural Correlations in Chalcogenide Glasses

1988 ◽  
Vol 135 ◽  
Author(s):  
P. Vashishta ◽  
José P. Rino ◽  
Rajiv K. Kalia
Keyword(s):  
Molecular Dynamics ◽  
Charge Transport ◽  
Chalcogenide Glasses ◽  
Pair Correlation ◽  
Diffusion Constant ◽  
Dynamics Simulation ◽  
Superionic Conductors ◽  
Static Structure Factor ◽  
Static Structure ◽  
Good Agreement

AbstractStructural properties, single-particle dynamics, and the charge transport are studied in superionic conductor Ag2Se using the molecular dynamics (MD) technique. The calculations are based on a model of interionic potentials in which ions interact through Coulomb interaction, steric repulsion and charge-dipole interaction due to the large electronic polarizability of the selenium ions. Structural and dynamics correlations are studied at five temperatures in the superionic phase. Among the structural correlations the results are presented for partial pair correlation function, coordination numbers, bond angle distributions and wave-vector dependence of the Bragg intensities. Detailed comparison with neutron and x-ray single crystal diffraction experiments. The calculated temperature dependence of the self-diffusion constant of silver is in good agreement with the tracer diffusion measurements. The spectra of velocity autocorrelation functions and the frequency dependent ionic conductivity are calculated. The Haven's ratio is also in good agreement with experiments.Effective interatomic potentials consisting of two-body (steric effect, charge transfer and charge-dipole interactions) and three-body covalent forces are proposed for GeSe2. Using these interaction potentials in MD simulations, the nature of short-range and medium-range order is investigated in glassy and molten GeSe2. All the features in the static structure factor, S(q), including the first sharp diffraction peak (FSDP), are in good agreement with experiments. The FSDP arises from Ge-Ge and Ge-Se correlations between 4-8Å, and the anomalous decrease in its height on cooling is due to frustration enhanced by the increased density.

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