scholarly journals Interatomic Forces and Bonding Mechanisms in MgO Clusters

1990 ◽  
Vol 193 ◽  
Author(s):  
Nancy F. Wright ◽  
Gayle S. Painter
Keyword(s):  
Interatomic Potentials ◽  
Many Body ◽  
Restoring Force ◽  
Mechanical Study ◽  
Quantum Mechanical Study ◽  
Force Curves ◽  
The Many ◽  
Quantum Treatment ◽  
Oxygen Ratio

ABSTRACTWe report results from a first-principles local spin density quantum mechanical study of the energetics and elastic properties of a series of magnesium-oxygen clusters of various morphologies. The role of quantum effects, e.g. covalency, in the bonding character of diatomic MgO is determined by comparison of classical and quantum restoring force curves. The dependence of binding properties on geometry and metal to oxygen ratio is determined by comparison of binding energy curves for a series of clusters. Results show that while gross features of the binding curves may be represented by simple interatomic potentials, details require the many body corrections of a full quantum treatment.

Elemental Interfaces and Displacive Phase Transformations

2008 ◽  
Vol 59 ◽  
pp. 63-68
Author(s):  
Václav Paidar
Keyword(s):  
Phase Transformations ◽  
Structural Changes ◽  
Atomic Plane ◽  
Many Body ◽  
Single Plane ◽  
Atomistic Models ◽  
Shear Type ◽  
Hcp Structure ◽  
The Many

Two basic processes, namely shear and shuffling of atomic planes can be considered as elementary mechanisms of displacive phase transformations. The atomistic models suitable to investigate the role of interfaces in the structural changes are tested. The many-body potentials are used for the description of interatomic forces. General displacements of atomic planes are examined, i.e. γ-surface type calculations extensively used for stacking fault and lattice dislocation analysis are applied to single plane shuffling and alternate shuffling of every other atomic plane producing in combination with homogeneous deformation the hcp structure. Similar approach considering shear type planar displacements leads to the Zener path between the bcc and fcc lattices. The effect of additional deformation required to obtain the close-packed atomic arrangements is analysed.

Role of the second nearest-neighbor hoppings in a disordered Bose–Hubbard Hamiltonian in the Many-Body Localization

2020 ◽  
Vol 93 (9) ◽  
Author(s):  
Edith Djoukouo Ngueyounou ◽  
Kanabet Yapara ◽  
Celsus Bouri ◽  
Hugues Merlain Tetchou Nganso ◽  
Moïse Godfroy Kwato Njock
Keyword(s):  
Nearest Neighbor ◽  
Many Body ◽  
Hubbard Hamiltonian ◽  
The Many

Modeling of supersonic crowdion clusters in FCC lattice: Effect of the interatomic potential

2021 ◽  
pp. 2050019
Author(s):  
Igor A. Shelepev ◽  
Ayrat M. Bayazitov ◽  
Elena A. Korznikova
Keyword(s):  
Interatomic Potential ◽  
High Energy ◽  
Propagation Path ◽  
Interatomic Potentials ◽  
Energy Localization ◽  
Many Body ◽  
Embedded Atom ◽  
Fcc Lattice ◽  
The Many ◽  
Body Potential

Among a wide variety of point defects, crowdions can be distinguished by their high energy of formation and relatively low migration barriers, which makes them an important agent of mass transfer in lattices subjected to severe plastic deformation, irradiation, etc. It was previously shown that complexes and clusters of crowdions are even more mobile than single interstitials, which opened new mechanisms for the transfer of energy and mass in materials under intense external impacts. One of the most popular and convenient methods for analyzing crowdions is molecular dynamics, where the results can strongly depend on the interatomic potential used in the study. In this work, we compare the characteristics of a crowdion in an fcc lattice obtained using two different interatomic potentials — the pairwise Morse potential and the many-body potential for Al developed by the embedded atom method. It was found that the use of the many-body potential significantly affects the dynamics of crowdion propagation, including the features of atomic collisions, the evolution of energy localization and the propagation path.

Role of the valence-band mass on the many-body optical properties of a two-dimensional electron gas

1998 ◽  
Vol 249-251 ◽  
pp. 603-606
Author(s):  
H.P van der Meulen ◽  
J Rubio ◽  
J.M Calleja ◽  
C Tejedor ◽  
F Rodriguez ◽  
...  
Keyword(s):  
Optical Properties ◽  
Valence Band ◽  
Electron Gas ◽  
Two Dimensional ◽  
Dimensional Electron ◽  
Many Body ◽  
Two Dimensional Electron Gas ◽  
Dimensional Electron Gas ◽  
The Many
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