scholarly journals Construction of Lennard-Jones pair potential and pairwise many-body potential for crystal α-boron

2015 ◽  
Vol 64 (10) ◽  
pp. 103401
Author(s):  
Yu Zhi-Qing ◽  
Wang Xun ◽  
Liu Yan-Xia ◽  
Wang Mei ◽  
Yang He ◽  
...  
Keyword(s):  
Pair Potential ◽  
Many Body ◽  
Lennard Jones ◽  
Body Potential

Defect Cluster Formation in High Energy Displacement Cascades in Copper

2000 ◽  
Vol 650 ◽  
Author(s):  
Yuri N. Osetsky ◽  
David J. Bacon
Keyword(s):  
Cluster Formation ◽  
Pair Potential ◽  
Simulation Method ◽  
High Energy ◽  
Interatomic Potentials ◽  
Dislocation Loops ◽  
Many Body ◽  
Displacement Cascades ◽  
Stacking Fault Tetrahedra ◽  
Body Potential

ABSTRACTPrimary radiation damage in displacement cascades in metals has been studied extensively by atomistic simulation during the last decade. The variety of defect types observed in cascade simulation is not entirely consistent with experimental data. For example, experiments on copper show a very effective production of stacking fault tetrahedra (SFTs) but this was not observed systematically in cascade simulation. To clarify this and related issues, extensive simulation of displacement cascades in copper have been performed using two different interatomic potentials, a short-range many-body potential and a long-range pair potential. We have studied the damage created by primary knock-on-atoms of energy up to 20keV, i.e. below the energy range for formation of subcascades, at temperatures 100 and 600K. Special attention was paid to cascade statistics and the accuracy of simulation in the collision stage. The former required many simulations for each temperature whereas the latter involved a modification of the simulation method. The results on variety of clusters observed, e.g. SFTs, glissile and sessile interstitial clusters, and faulted and perfect interstitial dislocation loops, lead to conclusions on the effect of the potentials and the significant variation of the number of Frenkel pairs and clustering effects produced in different cascades under the same conditions.

scholarly journals Базовые элементы структуры границ зерен наклона. Часть 2. Оси разориентации [110] и [111]-=SUP=-*-=/SUP=-

2021 ◽  
Vol 63 (1) ◽  
pp. 55
Author(s):  
А.В. Векман ◽  
Б.Ф. Демьянов
Keyword(s):  
Grain Boundaries ◽  
Atomic Structure ◽  
Pair Potential ◽  
Structural Vacancy ◽  
Many Body ◽  
Structural Units ◽  
Symmetric Tilt ◽  
Vacancy Model ◽  
Body Potential ◽  
Misorientation Angles

The computer simulation methods have been applied to calculate structure and energy of symmetric tilt grain boundaries (GB) with the misorientation axes [110] and [111]. The calculations have been carried out with the use of the structural-vacancy model. The study of the atomic structure has been carried out within the entire range of misorientation angles. The reverse density of coincidence sites in special grain boundaries has amounted Σ≤57. The calculations have been carried out with the use of the Morse pair potential and the Cleri-Rosato many-body potential. When calculated with different potentials, the dependence of GB energy on the misorientation angle has a similar form, and the atomic structure completely coincides. It has been shown that the structure of any GB with the misorientation axes [110] and [111] may be represented by a limited number of basic structural units. All found basic structural units defined as units of A, B, C and D types are based on the structures of special grain boundaries. Such special GBs shall be Σ3(111), Σ3(112), Σ11(113) and Σ9(114) for GBs with the misorientation axis [110], and as regarding GBs with the misorientation axis [111], such special GBs shall be Σ3(112), Σ7(123) and Σ13(134). Ranges of angles within which certain basic structural units are found have been defined.

Data-Driven Many-Body Models with Chemical Accuracy for CH4/H2O Mixtures

2020 ◽  
Author(s):  
Marc Riera ◽  
Alan Hirales ◽  
Raja Ghosh ◽  
Francesco Paesani
Keyword(s):  
Liquid Phase ◽  
Quantitative Description ◽  
Liquid Mixtures ◽  
Many Body ◽  
Energy Functions ◽  
Potential Energy Functions ◽  
Dynamics Simulations ◽  
Body Potential ◽  
Small Clusters ◽  
Many Body Interactions

<div> <div> <div> <p>Many-body potential energy functions (PEFs) based on the TTM-nrg and MB-nrg theoretical/computational frameworks are developed from coupled cluster reference data for neat methane and mixed methane/water systems. It is shown that that the MB-nrg PEFs achieve subchemical accuracy in the representation of individual many-body effects in small clusters and enables predictive simulations from the gas to the liquid phase. Analysis of structural properties calculated from molecular dynamics simulations of liquid methane and methane/water mixtures using both TTM-nrg and MB-nrg PEFs indicates that, while accounting for polarization effects is important for a correct description of many-body interactions in the liquid phase, an accurate representation of short-range interactions, as provided by the MB-nrg PEFs, is necessary for a quantitative description of the local solvation structure in liquid mixtures. </p> </div> </div> </div>

scholarly journals The phase diagram of carbon dioxide from correlation functions and a many-body potential

2021 ◽  
Vol 155 (2) ◽  
pp. 024503
Author(s):  
Amanda A. Chen ◽  
Alexandria Do ◽  
Tod A. Pascal
Keyword(s):  
Carbon Dioxide ◽  
Phase Diagram ◽  
Correlation Functions ◽  
Many Body ◽  
Body Potential

scholarly journals $$\hbox {Ag}_{m} \hbox {Rh}_n$$ clusters with $$m+n\le 55$$

2021 ◽  
Vol 140 (4) ◽  
Author(s):  
Nicolas Louis ◽  
Stephan Kohaut ◽  
Michael Springborg
Keyword(s):  
Genetic Algorithms ◽  
Structure Optimization ◽  
Structural Similarity ◽  
Similarity Function ◽  
Many Body ◽  
Coordination Numbers ◽  
Energetic Properties ◽  
Ag Clusters ◽  
Body Potential ◽  
Mixed Clusters

AbstractUsing a combination of genetic algorithms for the unbiased structure optimization and a Gupta many-body potential for the calculation of the energetic properties of a given structure, we determine the putative total-energy minima for all $$\hbox {Ag}_{m} \hbox {Rh}_n$$ Ag m Rh n clusters with a total number of atoms $$m+n$$ m + n up to 55. Subsequently, we use various descriptors to analyze the obtained structural and energetic properties. With the help of a similarity function, we show that the pure Ag and Rh clusters are structurally similar for sizes up to around 20 atoms. The same approach gives that the mixed clusters tend to possess a larger structural similarity with the pure Rh clusters than with the pure Ag clusters. However, for clusters with $$m\simeq n\ge 25$$ m ≃ n ≥ 25 , other structures dominate. The effective coordination numbers for the Ag and Rh atoms as well as the radial distributions of those atoms indicate that there is a tendency towards segregation with Rh atoms forming an inner part and the Ag atoms forming a shell. Only few clusters, all with a fairly large total number of atoms, are found to be particularly stable.

Mechanical and Tribological Properties of Carbon Nanotubes Investigated with Atomistic Simulations

2000 ◽  
Vol 633 ◽  
Author(s):  
Boris Ni ◽  
Susan B. Sinnott
Keyword(s):  
Carbon Nanotubes ◽  
Atomistic Simulations ◽  
Many Body ◽  
Jones Potential ◽  
Diamond Surfaces ◽  
Empirical Potential ◽  
Mechanical And Tribological Properties ◽  
Lennard Jones ◽  
Walled Carbon Nanotubes ◽  
Nanotube Bundle

AbstractAtomistic simulations are used to better understand the behavior of bundles of single- walled carbon nanotubes that have been placed between two sliding diamond surfaces. A many-body reactive empirical potential for hydrocarbons that has been coupled to a Lennard-Jones potential is used to determine the energies and forces for all the atoms in the simulations. The results indicate that the degree of compression of the nanotube bundle between the nanotubes has a significant effect on the responses of the nanotubes to shear forces. However, no rolling of the nanotubes is predicted in contrast to previous studies of individual nanotubes moving on graphite.

Empirical many-body potential energy functions for iron

1993 ◽  
Vol 97 (46) ◽  
pp. 12073-12082 ◽  
Author(s):  
Fei Gao ◽  
Roy L. Johnston ◽  
John N. Murrell
Keyword(s):  
Potential Energy ◽  
Many Body ◽  
Energy Functions ◽  
Potential Energy Functions ◽  
Body Potential

scholarly journals Study of Zero Temperature Ground State Properties of the Repulsive Bose-Einstein Condensate in an Anharmonic Trap

2021 ◽  
Vol 13 (3) ◽  
pp. 733-744
Author(s):  
P. K. DEBNATH
Keyword(s):  
Ground State ◽  
Expansion Method ◽  
Einstein Condensate ◽  
Zero Temperature ◽  
Many Body ◽  
Ground State Properties ◽  
Potential Harmonic ◽  
The Stability ◽  
Average Size ◽  
Body Potential

The zero-temperature ground state properties of experimental 87Rb condensate are studied in a harmonic plus quartic trap [ V(r) =  ½mω2r2 + λr4 ]. The anharmonic parameter (λ) is slowly tuned from harmonic to anharmonic. For each choice of λ, the many-particle Schrödinger equation is solved using the potential harmonic expansion method and determines the lowest effective many-body potential. We utilize the correlated two-body basis function, which keeps all possible two-body correlations. The use of van der Waals interaction gives realistic pictures. We calculate kinetic energy, trapping potential energy, interaction energy, and total ground state energy of the condensate in this confining potential, modelled experimentally. The motivation of the present study is to investigate the crucial dependency of the properties of an interacting quantum many-body system on λ. The average size of the condensate has also been calculated to observe how the stability of repulsive condensate depends on anharmonicity. In particular, our calculation presents a clear physical picture of the repulsive condensate in an anharmonic trap.

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