Electrostatic field gradients in ionic crystals

1964 ◽  
Vol 17 (1) ◽  
pp. 1 ◽  
Author(s):  
CK Coogan
Keyword(s):  
Field Gradient ◽  
Electrostatic Field ◽  
Point Charge ◽  
Ionic Crystals ◽  
Point Charge Model ◽  
Boundary Shape ◽  
Field Gradients ◽  
Charge Model

The convergence of the sums arising in the calculation of the electrostatic field gradient in crystals is discussed. In the point charge model of ionic crystals convergence ensues for any boundary shape, and not only for spheres. The method outlined is applied to Cu2O and NaClO3, and agreement obtained with previous work. The advantages of this method of computation are outlined.

Assignment and structural dependence of electric field gradients in anorthite and simple field gradient calculations in some aluminosilicates

1974 ◽  
Vol 140 (5-6) ◽  
Author(s):  
J. L. Staehli ◽  
D. Brinkmann
Keyword(s):  
Electric Field ◽  
Field Gradient ◽  
Quadrupole Coupling Constant ◽  
Coupling Constant ◽  
Electric Field Gradients ◽  
Point Charge Model ◽  
Polarization Effects ◽  
Field Gradients ◽  
Charge Model ◽  
Quadrupole Coupling

AbstractThe electric field gradient tensors at theIt was found that the quadrupole coupling constant is correlated with the distortion of the coordination tetrahedra and that the simple point-charge model which neglects polarization effects is apt to yield quite satisfying results for very distorted tetrahedra.Similar results were obtained for the Al and Na sites in albite, NaAlSi

Electric Field Gradient Modulation in Incommensurate Systems X2YZ4

1986 ◽  
Vol 41 (1-2) ◽  
pp. 256-260
Author(s):  
J. Pirnat ◽  
J. Lužnik ◽  
Z. Trontelj
Keyword(s):  
Electric Field ◽  
Electric Field Gradient ◽  
Field Gradient ◽  
Point Charge ◽  
Reasonable Agreement ◽  
Point Charge Model ◽  
Resonant Nucleus ◽  
Charge Model ◽  
The Subject ◽  
Wave Limit

The subject of the paper is the plane wave limit of static incommensurate displacement modulation in the crystal structure, which is related to the commensurate ferrophase modulation. Using the point charge model, the corresponding electric field gradient modulation and quadrupole perturbed NMR spectra are calculated. The corrections up to the 4th order owing to the incoherent displacements of the charges in the vicinity of the resonant nucleus are considered. Comparison with the experimental data shows a reasonable agreement.

scholarly journals Theoretical Study of the Electric Field Gradient in Silver Iodide

1992 ◽  
Vol 47 (1-2) ◽  
pp. 182-188
Author(s):  
G. Frantz ◽  
R. Leiberich ◽  
P. C. Schmidt
Keyword(s):  
Band Structure ◽  
Electric Field ◽  
Electric Field Gradient ◽  
Field Gradient ◽  
Point Charge ◽  
Cluster Approach ◽  
Point Charge Model ◽  
Hartree Fock ◽  
Charge Model ◽  
Theoretical Results

AbstractThe electric field gradient (EFG) in hexagonal Agl at the iodine site is studied theoretically by three different procedures, namely the point charge model, the Hartree-Fock cluster approach, and the augmented plane wave band structure procedure. A comparison is made for the electronic charge distribution and the sizes of the various contributions to the EFG obtained by the different procedures. From the point charge model and the Hartree-Fock cluster approach one gets almost the same result for the EFG, q = +0.743 • 1021 V/m2 and +0.816 • 1021 V/m2 respectively. Only a rather preliminary result of q = +0.393 • 1021 V/m2 is found by the band structure calculation to be compared with the experimental value of qexp= ±0.415 • 1021 V/m2 . The confidence limits of the theoretical results are discussed, including possible ways to bridge the gap between the theoretical results by different methods and experiment. Both the cluster and the band structure calculations are shown to support an ionic model for hexagonal Agl with some overlap between the charge distributions on neighboring ions.

Electric field gradient at Cu nucleaus in CuO: single-crystal NMR determination and point charge model

1991 ◽  
Vol 181 (1-3) ◽  
pp. 121-126 ◽  
Author(s):  
L. Cristofolini ◽  
G. Amoretti ◽  
C. Bucci ◽  
P. Carretta ◽  
R. De Renzi ◽  
...  
Keyword(s):  
Electric Field ◽  
Single Crystal ◽  
Electric Field Gradient ◽  
Field Gradient ◽  
Point Charge ◽  
Point Charge Model ◽  
Charge Model

Parametrizing a polarizable force field from ab initio data. I. The fluctuating point charge model

1999 ◽  
Vol 110 (2) ◽  
pp. 741-754 ◽  
Author(s):  
Jay L. Banks ◽  
George A. Kaminski ◽  
Ruhong Zhou ◽  
Daniel T. Mainz ◽  
B. J. Berne ◽  
...  
Keyword(s):  
Force Field ◽  
Ab Initio ◽  
Point Charge ◽  
Point Charge Model ◽  
Polarizable Force Field ◽  
Charge Model
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