The electric field gradient at the position of copper in Cu2O and electronic charge density analysis by means of K-factors

We present, for the first time, clear experimental evidence of the influence of the electronic configuration of probe-atoms on the temperature dependence of the electric-field gradient (EFG) tensor at impurity sites. We measured the EFG at 111 In →111 Cd and 181 Hf → 181 Ta impurity sites in a complete series of semiconducting and insulating compounds with the same crystalline structure, using the Perturbed-Angular-Correlation technique. The results of this systematic study show that while the principal component VZZ of the EFG increases with temperature at Cd-impurity sites, it decreases at Ta-impurity sites. This temperature dependence is associated with the redistribution of the electronic charge lack or excess located at the impurity center. A simple model is presented based on charge transfer from the probe to its neighbors, in terms of the acceptor and donor nature of the mentioned impurities.

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Influence of Electric Field in the Adsorption of Atomic Hydrogen on Graphene

Advances in Condensed Matter Physics ◽

10.1155/2015/847804 ◽

2015 ◽

Vol 2015 ◽

pp. 1-9 ◽

Cited By ~ 4

Author(s):

C. Cab ◽

R. Medina-Esquivel ◽

C. Acosta ◽

J. Mendez-Gamboa ◽

F. Peñuñuri ◽

...

Keyword(s):

Electric Field ◽

Charge Density ◽

Electric Fields ◽

Atomic Hydrogen ◽

Density Functional ◽

Electronic Charge ◽

Generalized Gradient ◽

Electronic Charge Density ◽

System A ◽

Spin Polarized

The influence of external electric field (EF) in the adsorption of atomic hydrogen on graphene (H/G) was studied by means of electronic structure calculations based on spin-polarized density functional theory with generalized gradient approximation (GGA). The changes in atomic hydrogen physisorption-chemisorption on graphene owed to EF (which ranged between −1.25 V/Å and 0.75 V/Å) were determined. Analysis of the electronic charge density for an H/G system explained the EF influences on the adsorption properties (analyzing changes in electronic charge density for H/G system). A decrease of more than 100% in the chemisorption barrier for an EF of −1.25 V/Å was found. The changes in the electronic charge density confirm the possibility of manipulating the physical-chemical adsorption of hydrogen on graphene by applying electric fields.

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Electric Field Gradient Tensor Distributions in 2-Dimensional Incommensurate Charge Density Wave Systems

Physica Scripta ◽

10.1238/physica.regular.063a00203 ◽

2001 ◽

Vol 63 (3) ◽

pp. 203-208 ◽

Cited By ~ 1

Author(s):

T Butz

Keyword(s):

Electric Field ◽

Electric Field Gradient ◽

Charge Density ◽

Field Gradient ◽

Charge Density Wave ◽

Density Wave ◽

Electric Field Gradient Tensor ◽

Gradient Tensor ◽

Tensor Distributions

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The topology of the valence shell and the electric field gradient at the nitrogen nucleus in aziridines

Canadian Journal of Chemistry ◽

10.1139/v96-125 ◽

1996 ◽

Vol 74 (6) ◽

pp. 1116-1120

Author(s):

Félix Rosillo ◽

Yosslen Aray ◽

Jesús Rodríguez ◽

Juan Murgich

Keyword(s):

Electric Field ◽

Electric Field Gradient ◽

Charge Density ◽

Field Gradient ◽

Valence Shell ◽

Nitrogen Nucleus ◽

Principal Axes ◽

Molecular Charge ◽

Charge Concentration ◽

C And N

The ab initio molecular charge density ρ(r) of substituted aziridines was calculated at the MP2 level for R = -H, -CH3, -CF3, -Cl, -NO2, -CN, -OH, -NO, and -F. The use of the topology of the Laplacian of ρ(r) allowed the analysis of the electric field gradient (EFG) at the nitrogen nucleus directly in terms of its valence shell charge concentration. The EFG changed sign and the orientation of its y- and z-axes with respect to aziridine when R = -Cl, -NO2, -CN, -OH, -NO, and -F. The changes in the EFG in these aziridines upon substitution were correlated with those calculated in the valence charge concentrations along the direction of the N—R bond. The sign of the qzz component and the orientation of the principal axes of the EFG tensor were found to be determined by the relative value of the contributions from the charge concentrations at the points in the valence shell along the N—C and N—R bond directions. Key words: molecular charge distribution, aziridines, Laplacian of the charge density, electric field gradient.

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