A novel semi-empirical potential for covalently bonded materials

1992 ◽  
Vol 194 (4-6) ◽  
pp. 363-369 ◽  
Author(s):  
L.René Corrales ◽  
Peter J. Rossky
Keyword(s):  
Empirical Potential ◽  
Bonded Materials ◽  
Covalently Bonded ◽  
Semi Empirical

Experimental determination of electric-field-induced differences in structure-factor phases of the order of 2%

1999 ◽  
Vol 55 (6) ◽  
pp. 1034-1037 ◽  
Author(s):  
J. Stahn ◽  
A. Pucher ◽  
U. Pietsch ◽  
J. Zellner ◽  
E. Weckert
Keyword(s):  
Electric Field ◽  
Structure Factor ◽  
Phase Variation ◽  
Bonded Materials ◽  
Charge Model ◽  
Covalently Bonded ◽  
Phase Variations ◽  
Bond Charge ◽  
Semi Empirical

In order to understand the induced electron-density response of covalently bonded materials to an externally applied electric field, the change of structure-factor phases of several weak reflections of GaAs has been measured by three-beam interferences. Using a modulation technique, phase variations of the order of 1° for a field strength of 1 kV mm−1 were determined. Although the statistics of these first experiments are rather poor, the experiment verifies qualitatively the predictions of a semi-empirical bond-charge model. The measured phase variation is the smallest value determined up to now.

The Sintering Behavior of Covalently-Bonded Materials

1977 ◽  
pp. 351-357 ◽  
Author(s):  
C. Greskovich ◽  
S. Prochazka ◽  
J. H. Rosolowski
Keyword(s):  
Sintering Behavior ◽  
Bonded Materials ◽  
Covalently Bonded

The melting transition of Ni7 and Ni7H as modeled by a semi-empirical potential

1998 ◽  
Vol 295 (4) ◽  
pp. 366-372 ◽  
Author(s):  
E Curotto ◽  
David L Freeman ◽  
Bin Chen ◽  
J.D Doll
Keyword(s):  
Melting Transition ◽  
Empirical Potential ◽  
Semi Empirical

Semi-Empirical Potential Methods for Atomistic Simulations of Metals and Their Construction Procedures

2009 ◽  
Vol 131 (4) ◽  
Author(s):  
Seong-Gon Kim ◽  
M. F. Horstemeyer ◽  
M. I. Baskes ◽  
Masoud Rais-Rohani ◽  
Sungho Kim ◽  
...  
Keyword(s):  
Material Properties ◽  
Density Functional ◽  
Embedded Atom Method ◽  
Functional Theory ◽  
Empirical Potential ◽  
Embedded Atom ◽  
Target Values ◽  
Potential Methods ◽  
Semi Empirical ◽  
Cohesive Energies

General theory of semi-empirical potential methods including embedded-atom method and modified-embedded-atom method (MEAM) is reviewed. The procedures to construct these potentials are also reviewed. A multi-objective optimization (MOO) procedure has been developed to construct MEAM potentials with minimal manual fitting. This procedure has been applied successfully to develop a new MEAM potential for magnesium. The MOO procedure is designed to optimally reproduce multiple target values that consist of important material properties obtained from experiments and first-principle calculations based on density-functional theory. The optimized target quantities include elastic constants, cohesive energies, surface energies, vacancy-formation energies, and the forces on atoms in a variety of structures. The accuracy of the present potential is assessed by computing several material properties of Mg including their thermal properties. We found that the new MEAM potential shows a significant improvement over previously published potentials, especially for the atomic forces and melting temperature calculations.

scholarly journals Theoretical and Experimental Techniques for the Determination of X-ray Anomalous Dispersion Corrections

1985 ◽  
Vol 38 (3) ◽  
pp. 371 ◽  
Author(s):  
Dudley Creagh
Keyword(s):  
Lithium Fluoride ◽  
Anomalous Dispersion ◽  
Experimental Techniques ◽  
X Ray ◽  
Bonded Materials ◽  
Theoretical Approaches ◽  
Covalently Bonded ◽  
Theoretical Predictions

Theoretical and experimental techniques for the determination of the X-ray anomalous dispersion corrections f'(w, LI) and fl/(w, LI) are discussed. The results of experiments on metallic, ionic and covalently bonded materials typified by copper and nickel, lithium fluoride, and silicon respectively are compared with the theoretical predictions. Attention is drawn to deficiencies in both the experimental and the theoretical approaches.

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