Simulation of Structure and Dynamics of Amorphous SiO2

1996 ◽  
Vol 446 ◽  
Author(s):  
Y. Kogure ◽  
M. Doyama
Keyword(s):  
Molecular Dynamics ◽  
Computer Simulation ◽  
Distribution Function ◽  
Radial Distribution Function ◽  
Radial Distribution ◽  
Amorphous Structure ◽  
Amorphous Sio2 ◽  
Coordination Numbers ◽  
Structure And Dynamics ◽  
External Stresses

AbstractA molecular dynamics computer simulation of amorphous SiO2 has been made to investigate the structure and dynamics. The effects of the external stresses on the amorphous structure were investigated through the radial distribution function, the distribution of Si‐O‐Si bond angles, and the distribution of coordination numbers.

Computer Simulation of Stress Distribution in Amorphous SiO2 Thin Films

1997 ◽  
Vol 505 ◽  
Author(s):  
Y. Kogure ◽  
M. Doyama
Keyword(s):  
Thin Films ◽  
Molecular Dynamics ◽  
Computer Simulation ◽  
Distribution Function ◽  
Molecular Dynamics Simulation ◽  
Internal Stress ◽  
Amorphous Structure ◽  
Dynamics Simulation ◽  
Atomic Configuration ◽  
Amorphous Sio2

ABSTRACTA molecular dynamics simulation of amorphous SiO2 thin films has been made to investigate the structure and internal stress. The atomic configuration of the amorphous structure is investigated through the radial distribution function and the distribution of Si-O-Si bond angles. Distribution of internal stress through the specimen is evaluated from the volume and the shape of the SiO4 tetrahedron, which is the elementally unit of amorphous SiO2.

Effect of Substrate Temperature and Incident Energy for Alloyzation of Co onto Cu(001) Substrate

2008 ◽  
Vol 47-50 ◽  
pp. 375-378 ◽  
Author(s):  
Zheng Han Hong ◽  
Shun Fa Hwang ◽  
Te Hua Fang
Keyword(s):  
Molecular Dynamics ◽  
Distribution Function ◽  
Substrate Temperature ◽  
Radial Distribution Function ◽  
Radial Distribution ◽  
Incident Energy

The mixing situation of Co atoms implanting onto Cu(001) substrate is investigated with regard to incident energy and substrate temperature by molecular dynamics. The results indicate that higher substrate temperature and/or incident energy will result in higher intermixing between the incident atoms and the substrate atoms. Furthermore, the value of the first peak of the radial distribution function (RDF) becomes lower and wider for the Co-Cu system as the substrate temperature and/or incident energy are increased.

scholarly journals Molecular Dynamics Study on the Leaching of Zinc-Bearing Dust Sludge by Choline Chloride-Malonic Acid

Minerals ◽  
2021 ◽  
Vol 11 (10) ◽  
pp. 1080
Author(s):  
Jinxia Zhang ◽  
Chao Yang ◽  
Fusheng Niu ◽  
Shuling Gao ◽  
Jiajing Dong
Keyword(s):  
Molecular Dynamics ◽  
Distribution Function ◽  
Metal Oxides ◽  
Radial Distribution Function ◽  
Malonic Acid ◽  
Radial Distribution ◽  
Choline Chloride ◽  
Leaching Rate ◽  
Single Factor ◽  
Leaching Experiments

Molecular dynamics of the interaction between four metal oxides (ZnO, Fe2O3, Al2O3, and CaO) present in zinc-bearing dust sludge and choline chloride (ChCl)-malonic acid (MA)(1:2) was studied in this work using Materials Studio software. The interaction mechanism was revealed by analyzing the interaction energy and radial distribution function from the perspective of quantum mechanics, and the simulation results were verified by single factor leaching experiments. The calculation results show that the complete cleavage surface of the four metal oxides is the (001) surface, and ChCl-2MA forms a stable structure with multiple intermolecular hydrogen bonds centered on the chlorine atom. The dynamic simulation of the interaction model shows that strength of interaction between ChCl-2MA and the four metal oxides follows the order: ZnO > Fe2O3 > Al2O3 > CaO. ChCl-2MA mainly interacts with ZnO by chemical adsorption, while ChCl-2MA mainly interacts with Fe2O3, Al2O3, and CaO by physical adsorption. The radial distribution function shows that Cl in ChCl-2MA and C=O in MA form chemical bonds with Zn in ZnO, and the choline cation (Ch+) forms C-H···O with ZnO. Among these bonds, the Cl-Zn bond energy is stronger. During the interaction between ChCl-2MA and Fe2O3 and Al2O3, O-H···O and C-H···O are formed and interact with CaO by van der Waals force. Single factor leaching experiments show that, under the same leaching conditions, the leaching rate of ZnO by ChCl-2MA is greater than 90%, while the leaching rate of Fe2O3, Al2O3, and CaO is about 10%. These results indicate good selectivity of ChCl-2MA for ZnO in the zinc-bearing dust sludge. The above conclusions have important theoretical significance and provide an in-depth understanding of the leaching mechanisms of zinc-bearing dust sludge in deep eutectic solvents.

scholarly journals Investigating the Compatibility of Various Components in Marine Low-Sulfur Fuel Oil by Molecular Dynamics Simulations

2021 ◽  
Vol 2021 ◽  
pp. 1-10
Author(s):  
Daping Zhou ◽  
Haijun Wei ◽  
Shuye Xue ◽  
Ye Qiu ◽  
Shen Wu ◽  
...  
Keyword(s):  
Molecular Dynamics ◽  
Distribution Function ◽  
Radial Distribution Function ◽  
Radial Distribution ◽  
Md Simulations ◽  
Peak Height ◽  
Fuel Oil ◽  
Solubility Parameters ◽  
Heavy Fuel Oil ◽  
Low Sulfur

Asphaltene aggregation and precipitation are one of the major issues for marine low-sulfur fuel oil used on board. Many research studies have been carried out to investigate the aggregation behavior of asphaltene under different conditions, but the mechanism of asphaltene aggregation in low-sulfur fuel oil at the molecular level is still unclear. In this work, molecular dynamics (MD) simulations were performed to calculate the solubility parameters, intermolecular interaction energies, and radial distribution function (RDF) curves of each component in marine low-sulfur fuel oil to examine their mutual compatibility. Simulation results indicate that the solubility parameter of resin gains the highest value and it is close to asphaltene. The solubility parameters of aromatic, hexadecane, and saturate decrease successively. The interaction energy between resin and asphaltene molecules is higher than that between the same kind of molecules, which means that resin can inhibit the aggregation of asphaltene molecules. Typically, a light distillate component (hexadecane) is added to heavy fuel oil to yield low-sulfur oil, and our calculations reveal that this has a negative effect on asphaltene aggregation. Specifically, asphaltene is more likely to self-aggregate, as shown by the increase in peak height in the radial distribution function of the asphaltene-asphaltene pair. The findings of this study will provide theoretical support for the production of marine low-sulfur fuel.

What first principles molecular dynamics can tell us about EXAFS spectroscopy of radioactive heavy metal cations in water

2009 ◽  
Vol 97 (7) ◽  
Author(s):  
Magali Duvail ◽  
Paola D'Angelo ◽  
Marie-Pierre Gaigeot ◽  
Pierre Vitorge ◽  
Riccardo Spezia
Keyword(s):  
Molecular Dynamics ◽  
Heavy Metal ◽  
Distribution Function ◽  
Molecular Dynamics Simulation ◽  
Radial Distribution Function ◽  
First Principles ◽  
Dynamics Simulation ◽  
Heavy Metal Cations ◽  
Structure And Dynamics ◽  
Water Solvent

AbstractIn this paper we show how molecular dynamics simulation can improve comprehension of structure and dynamics of water solvent around heavy cations. In particular, metal-water radial distribution function obtained from molecular dynamics can be used into EXAFS equation to improve the experimental signal fitting. Here we show results on structure and dynamics of Co

Study on Ni/Al Interface Diffusion at Initial Time by Using Molecular Dynamics Method

2011 ◽  
Vol 391-392 ◽  
pp. 42-45 ◽  
Author(s):  
Yu Mei Dai ◽  
Sheng Long Zhu ◽  
Fu Hui Wang
Keyword(s):  
Molecular Dynamics ◽  
Distribution Function ◽  
Radial Distribution Function ◽  
Radial Distribution ◽  
Diffusion Theory ◽  
Interface Reaction ◽  
Initial Time ◽  
Diffusion Layer Thickness ◽  
Interface Diffusion ◽  
The Matrix

The basic theory of molecular dynamics and interface diffusion theory are used to simulate metal Ni/Al interface diffusion. The position image of the interface diffusion atoms and radial distribution function curve of Ni/Al interface reaction at initial time at a high temperature can be got. Through these images of diffusion atoms position, it is observed that there is a lot of change during the simulation process. The Al atoms layer of the matrix begins to melt at first. Ni atoms in the matrix begin to diffuse outward rapidly in large quantities. Al atoms overall diffuse to one side of the matrix at a relatively low speed, inter-diffusion layer thickness increases continuously and inter-diffusion atoms are solidified gradually from one side of the matrix to the surface. The process of change has been further verified in the corresponding radial distribution function curves. These conclusions can provide a theoretical reference for the technology of new materials preparation and the expansion of the environment of Ni/Al use.

Molecular dynamics studies the effect of structure MgSiO3 bulk on formation process geology of the Earth

2019 ◽  
Vol 08 (03) ◽  
pp. 1950011 ◽  
Author(s):  
Nguyen Trong Dung ◽  
Nguyen Chinh Cuong ◽  
Duong Quoc Van
Keyword(s):  
Molecular Dynamics ◽  
Distribution Function ◽  
Total Energy ◽  
Radial Distribution Function ◽  
Radial Distribution ◽  
Formation Process ◽  
Pair Interaction ◽  
Effect Of Temperature ◽  
Angle Distribution ◽  
The Earth

The paper studies the effect of temperature ([Formula: see text]), ([Formula: see text], 3200, 4000, 5000, 6000, 7000[Formula: see text]K) at pressure [Formula: see text][Formula: see text]GPa; pressure ([Formula: see text]), ([Formula: see text], 100, 200, 300, 350, 400[Formula: see text]GPa) at [Formula: see text][Formula: see text]K and thermal annealing time ([Formula: see text]), [Formula: see text][Formula: see text]ps (after 105 steps) at [Formula: see text][Formula: see text]K, [Formula: see text][Formula: see text]Gpa) on the structure of MgSiO3 bulk 3000 atoms by Molecular Dynamics (MD) simulation using Born–Mayer (BM) pair interaction potential and periodic boundary conditions. The structural results are analyzed through the Radial Distribution Function (RDF), the Coordination Number (CN), the angle distribution, size ([Formula: see text]), total energy of the system ([Formula: see text]) and the bonding lengths. The results show that the temperature and pressure had influenced the structural properties of MgSiO3 bulk and formation process geology of the Earth. In addition, the center of the Earth with [Formula: see text][Formula: see text]K and [Formula: see text][Formula: see text]GPa has appearance and disappearance of the Si–Si, Si–O, O–O, Si–Mg, O–Mg, Mg–Mg bonds and SiO4, SiO5, SiO6, MgO3, MgO4, MgO5, MgO6, MgO7, MgO8, MgO9, MgO[Formula: see text], MgO[Formula: see text], MgO[Formula: see text] angle distributions. When increasing the depth of the Earth’s surface [Formula: see text] lead to size [Formula: see text] of MgSiO3 decreases, total energy of the system ([Formula: see text]) increases, position of first peak of Radial Distribution Function (RDF) is [Formula: see text], height of RDF is [Formula: see text] varies greatly with [Formula: see text] from [Formula: see text][Formula: see text]km to [Formula: see text][Formula: see text]km, gradually decreasing with [Formula: see text] from [Formula: see text][Formula: see text]km to [Formula: see text][Formula: see text]km and the smallest structural change with [Formula: see text][Formula: see text]km that shows has influence affects on the geological formation of the Earth.

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