scholarly journals Investigation of Microscopic Structure and Ion Dynamics in Liquid Li(Na, K)EutecticCl Systems by Molecular Dynamics Simulation

2018 ◽  
Vol 8 (10) ◽  
pp. 1874 ◽  
Author(s):  
Jie Wu ◽  
Jia Wang ◽  
Haiou Ni ◽  
Guimin Lu ◽  
Jianguo Yu
Keyword(s):  
Molecular Dynamics ◽  
Ionic Conductivity ◽  
Shear Viscosity ◽  
Ion Pairs ◽  
Liquid Structure ◽  
Distribution Functions ◽  
Dynamics Simulation ◽  
Molten Chloride ◽  
Ion Clusters ◽  
Self Diffusion

Molten chloride salts are the main components in liquid metal batteries, high-temperature heat storage materials, heat transfer mediums, and metal electrolytes. In this paper, interest is centered on the influence of the LiCl component and temperature on the local structure and transport properties of the molten LiCl-NaCl-KCl system over the temperature range of 900 K to 1200 K. The liquid structure and properties have been studied across the full composition range by molecular dynamics (MD) simulation of a sufficient length to collect reliable values, such as the partial radial distribution function, angular distribution functions, coordination numbers distribution, density, self-diffusion coefficient, ionic conductivity, and shear viscosity. Densities obtained from simulations were underestimated by an average 5.7% of the experimental values. Shear viscosities and ionic conductivity were in good agreement with the experimental data. The association of all ion pairs (except for Li-Li and Cl-Cl) was weakened by an increasing LiCl concentration. Ion clusters were formed in liquids with increasing temperatures. The self-diffusion coefficients and ionic conductivity showed positive dependences on both LiCl concentration and temperature, however, the shear viscosity was the opposite. By analyzing the hydrodynamic radii of each ion and the coordination stability of cation-anion pairs, it was speculated that ion clusters could be the cation-anion coordinated structure and affected the macro properties.

Molecular dynamics simulation of interhalogen compounds. 1. Liquid chlorine trifluoride (ClF3): structure and thermodynamics

1992 ◽  
Vol 70 (1) ◽  
pp. 34-38 ◽  
Author(s):  
Ramesh K. Wadi ◽  
Vivek Saxena
Keyword(s):  
Molecular Dynamics ◽  
Thermodynamic Properties ◽  
Md Simulation ◽  
Pair Potential ◽  
Liquid Structure ◽  
Spectroscopic Studies ◽  
Distribution Functions ◽  
Dynamics Simulation ◽  
Self Diffusion ◽  
Laser Raman

The results of a molecular dynamics (MD) simulation study of liquid chlorine trifluoride (ClF3) at 217, 260, and 287 K are reported. The cubic simulation cell consists of 108 ClF3 molecules assumed to be interacting via site–site Lennard–Jones 12–6 pair potential. The parameters for F–F and Cl–Cl interaction are the same as used for the simulation of F2, and Cl2, respectively, and those for the Cl–F cross interaction are calculated using Lorentz–Berthelot rules. These results are then used to calculate various radial distribution functions characteristic of the liquid structure. Thermodynamic properties, namely, configurational energy, constant volume specific heat, and internal pressure are also reported. The time-dependent properties, mean square force and torque, self diffusion coefficient, and the quantum corrections to the free energy, were also obtained. The dimer configuration drawn based on the observed contact distances was found to be in good agreement with the results of matrix isolation infrared and laser Raman spectroscopic studies. Keywords: MD simulation, interhalogens, liquid structure, thermodynamic properties.

Structure and Dynamics of NaCl in Methanol. A Molecular Dynamics Study

1991 ◽  
Vol 46 (10) ◽  
pp. 887-897 ◽  
Author(s):  
D. Marx ◽  
K. Heinzinger ◽  
G. Pálinkás ◽  
I. Bakó
Keyword(s):  
Molecular Dynamics ◽  
Diffusion Coefficients ◽  
Distribution Functions ◽  
Dynamics Simulation ◽  
Nacl Solution ◽  
Geometrical Arrangement ◽  
Self Diffusion ◽  
Site Model ◽  
Structure And Dynamics ◽  
Dynamical Properties

AbstractA recently developed flexible three-site model for methanol was employed to perform a Molecular Dynamics simulation of a 0.6 molal NaCl solution. The ion-methanol and ion-ion potential functions were derived from ab initio calculations. The structural properties of the solution are discussed on the basis of radial and angular distribution functions, the orientation of the methanol molecules, and their geometrical arrangement in the solvation shells of the ions. The dynamical properties of the solution - like self-diffusion coefficients, hindered translations, librations, and internal vibrations of the methanol molecules - are calculated from various autocorrelation functions.

Molecular Dynamics Study of a Lithium Ion in Ammonia

1988 ◽  
Vol 43 (6) ◽  
pp. 572-582 ◽  
Author(s):  
S. V. Hannongbua ◽  
T. Ishida ◽  
E. Spohr ◽  
K. Heinzinger
Keyword(s):  
Molecular Dynamics ◽  
Lithium Ion ◽  
Solvation Shell ◽  
Distribution Functions ◽  
Dynamics Simulation ◽  
Self Diffusion ◽  
Average Temperature ◽  
Self Diffusion Coefficient ◽  
Flexible Model ◽  
N Vector

Abstract A Molecular Dynamics simulation of a solution of one Li+ in 215 NH3 molecules has been performed at an average temperature of 235 K. A newly developed flexible model for NH3 is employed and the Li +−NH3 interactions are derived from ab initio calculations. The structure of the solution is described by radial distribution functions and the orientation of the molecules. A solvation number of six is found for Li+ and a strong preference of the solvation shell molecules exists for an orientation where the Li + −N vector and the dipole moment direction of NH3 are parallel. The self-diffusion coefficient, the hindered translational motions and librations are calculated separately for the ammonia molecules in the solvation shell and in the bulk. The effect of Li + on intramolecular geometry and vibrations is reported.

scholarly journals Estimation of the Enrichment of Cs in Molten Chloride and Fluoride Systems by Molecular Dynamics Simulation

2001 ◽  
Vol 56 (3-4) ◽  
pp. 279-287 ◽  
Author(s):  
Masahiko Matsumiya ◽  
Ryuzo Takagi
Keyword(s):  
Molecular Dynamics ◽  
Molecular Dynamics Simulation ◽  
Diffusion Coefficients ◽  
The Self ◽  
Dynamics Simulation ◽  
Molten Chloride ◽  
Self Diffusion ◽  
Metallic Fuels ◽  
Relative Differences ◽  
Pyrochemical Reprocessing

Abstract For the pyrochemical reprocessing of spent metallic fuels in molten salt baths it is of importance to estimate the enrichment degree of Cs. A molecular dynamics simulation has been executed on molten (Li, Na, Cs)Cl at 900 K and (Li, Na, Cs)F at 925 K for various compositions in order to calculate the relative differences in the internal cation mobilities of Cs in molten LiCl-NaCl equimolar mixtures and the LiF-NaF eutectic. According to these results the self-exchange velocities of Li+, Na+ and Cs+ with respect to Cl- and F- have similar tendencies at each composition, and Cs can be enriched effectively up to xCs = 0.5 -0.6 in LiCl-NaCl melts. In addition, the sequence of the calculated self-diffusion coefficients for various compositions was in a fair agreement with that of the obtained self-exchange velocities.

scholarly journals Molecular Dynamics Simulation on the Interaction between Palygorskite Coating and Linear Chain Alkane Base Lubricant

Coatings ◽  
2021 ◽  
Vol 11 (3) ◽  
pp. 286
Author(s):  
Jin Zhang ◽  
Lv Yang ◽  
Yue Wang ◽  
Huaichao Wu ◽  
Jiabin Cai ◽  
...  
Keyword(s):  
Molecular Dynamics ◽  
Structural Changes ◽  
Molecular Diffusion ◽  
Linear Chain ◽  
Interfacial Interaction ◽  
Dynamics Simulation ◽  
Electrostatic Energy ◽  
Experimental Development ◽  
Practical Applications ◽  
Self Diffusion

Molecular dynamics (MD) simulations were conducted to investigate the interactions between a palygorskite coating and linear chain alkanes (dodecane C12, tetradecane C14, hexadecane C16, and octadecane C18), representing base oils in this study. The simulation models were built by placing the alkane molecules on the surface of the palygorskite coating. These systems were annealed and geometrically optimized to obtain the corresponding stable configurations, followed by the analysis of the structural changes occurring during the MD process. The interfacial interaction energies, mean square displacements, and self-diffusion coefficients of the systems were evaluated to characterize the interactions between base lubricant molecules and palygorskite coating. It was found that the alkanes exhibited self-arrangement ability after equilibrium. The interfacial interaction was attractive, and the electrostatic energy was the main component of the binding energy. The chain length of the linear alkanes had a significant impact on the intensity of the interfacial interactions and the molecular diffusion behavior. Moreover, the C12 molecule exhibited higher self-diffusion coefficient values than C14, C16 and C18. Therefore, it could be the best candidate to form an orderliness and stable lubricant film on the surface of the palygorskite coating. The present work provides new insight into the optimization of the structure and composition of coatings and lubricants, which will guide the experimental development of these systems for practical applications.

scholarly journals Self-diffusion of Fe and Pt in L1-Ordered FePt: Molecular Dynamics simulation

2021 ◽  
Vol 192 ◽  
pp. 110337
Author(s):  
S.I. Konorev ◽  
R. Kozubski ◽  
M. Albrecht ◽  
I.A. Vladymyrskyi
Keyword(s):  
Molecular Dynamics ◽  
Molecular Dynamics Simulation ◽  
Dynamics Simulation ◽  
Self Diffusion

Self-diffusion of lignite/water under different temperatures and pressure: A molecular dynamics study

2016 ◽  
Vol 30 (01) ◽  
pp. 1550253 ◽  
Author(s):  
Xinjian Liu ◽  
Yu Jin ◽  
Congliang Huang ◽  
Jingfeng He ◽  
Zhonghao Rao ◽  
...  
Keyword(s):  
Molecular Dynamics ◽  
Water System ◽  
Simulation Method ◽  
The Self ◽  
Dynamics Simulation ◽  
Low Rank ◽  
Self Diffusion ◽  
Change Mechanism ◽  
Different Temperatures ◽  
Temperature And Pressure

Temperature and pressure have direct and remarkable implications for drying and dewatering effect of low rank coals such as lignite. To understand the microenergy change mechanism of lignite, the molecular dynamics simulation method was performed to study the self-diffusion of lignite/water under different temperatures and pressure. The results showed that high temperature and high pressure can promote the diffusion of lignite/water system, which facilitates the drying and dewatering of lignite. The volume and density of lignite/water system will increase and decrease with temperature increasing, respectively. Though the pressure within simulation range can make lignite density increase, the increasing pressure showed a weak impact on variation of density.

Structural and Mechanical Properties of Nanophase Ni: A Molecular-Dynamics Study of the Influence of Grain-Boundary Structure on Elastic and Plastic Behavior

1997 ◽  
Vol 492 ◽  
Author(s):  
H. Van Swygenhoven ◽  
M. Spaczér ◽  
A. Caro
Keyword(s):  
Molecular Dynamics ◽  
Grain Boundary ◽  
Grain Boundaries ◽  
Diffusion Mechanism ◽  
Distribution Functions ◽  
Boundary Structure ◽  
Plastic Behavior ◽  
Self Diffusion ◽  
Common Neighbour ◽  
Grain Boundary Structure

ABSTRACTMolecular dynamics computer simulations of high load plastic deformation at temperatures up to 500K of Ni nanophase samples with mean grain size of 5 nm are reported. Two types of samples are considered: a polycrystal nucleated from different seeds, each having random location and random orientation, representing a sample with mainly high angle grain boundaries, and polycrystals with seeds located at the same places as before, but with a limited missorientation representing samples with mainly low angle grain boundaries. The structure of the grain boundaries is studied by means of pair distribution functions, coordination number, atom energetics, and common neighbour analysis. Plastic behaviour is interpreted in terms of grain-boundary viscosity, controlled by a self diffusion mechanism at the disordered interface activated by thermal energy and stress.

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