Bonding in negative ions: the role of d orbitals in the heavy analogues of pyridine and furanradical anions

2011 ◽  
Vol 13 (4) ◽  
pp. 1663-1668 ◽  
Author(s):  
Balázs Hajgató ◽  
Frank De Proft ◽  
Dénes Szieberth ◽  
David J. Tozer ◽  
Michael S. Deleuze ◽  
...  
Keyword(s):  
Negative Ions ◽  
D Orbitals

scholarly journals Single-Photon Multiple Detachment in Fullerene Negative Ions: Absolute Ionization Cross Sections and the Role of the Extra Electron

2013 ◽  
Vol 111 (4) ◽  
Author(s):  
R. C. Bilodeau ◽  
N. D. Gibson ◽  
C. W. Walter ◽  
D. A. Esteves-Macaluso ◽  
S. Schippers ◽  
...  
Keyword(s):  
Cross Sections ◽  
Single Photon ◽  
Negative Ions ◽  
Ionization Cross ◽  
Extra Electron ◽  
Ionization Cross Sections

scholarly journals Some aspects of ion-acoustic whistlers in the ionosphere in the presence of negative ions

1989 ◽  
Vol 12 (4) ◽  
pp. 749-772 ◽  
Author(s):  
A. K. Sur ◽  
G. C. Das ◽  
B. Chakraborty ◽  
S. N. Paul ◽  
L. Debnath
Keyword(s):  
Travel Time ◽  
Critical Frequency ◽  
Cyclotron Frequency ◽  
Negative Ions ◽  
Induced Magnetic Field ◽  
Ion Acoustic ◽  
Phase And Group Velocities ◽  
Group Velocities ◽  
Group Travel

A study is made of the propagation of ion-acoustic whistlers in the atmosphere including the effects of negative ions. The dispersion relation, phase and group velocities of whistlers are discussed. It is shown that the presence of negative ions introduces a critical frequency which, for equal ionic masses, is equal to the ion-cyclotron frequency. Special attention is given to the group travel time of whistlers at mid-latitude and equator so that the role of negative ions on the group travel time can be determined. The cyclotron damping of whistlers in the presence of negative ions has been studied. The velocity distribution, total attenuation and the induced magnetic field are calculated from the temporal as well as spatial cyclotron damping. It is suggested that the attenuation of whistlers may cause heating of the ionosphere. It is also indicated that the measurement of the group travel time from its source to the observer at the satellite would help to diagnose the ionospheric parameters. The results of the analysis are presented by several graphical presentations.

scholarly journals Детерминизм локального атомного упорядочения в монослоях золота в формировании их электронной структуры

2022 ◽  
Vol 64 (3) ◽  
pp. 303
Author(s):  
В.Л. Карбовский ◽  
А.А. Романский ◽  
Л.И. Карбовская ◽  
В.В. Стонис
Keyword(s):  
Coordination Sphere ◽  
Electronic States ◽  
Mutual Arrangement ◽  
Quantum Mechanical ◽  
Quantum Mechanical Calculations ◽  
The Third ◽  
Long Range Interactions ◽  
Valence Bands ◽  
D Orbitals

The total and partial densities of electronic states of gold monolayer structures of different symmetry are calculated by the quantum mechanical calculations methods in the DFT approximation. It is shown that the first coordination sphere is determinant in the formation of the fine structure and the extent of the valence bands of the monolayer gold structures under study. The peaks splitting of the TDOS curve, which leads to its finer structure, is influenced not only by the lengths of interatomic bonds but also by the mutual arrangement of atoms. The influence of long-range interactions on the electronic structure of gold monolayers has been established. For example, for the (110) plane, a change in the atomic ordering in the third coordination sphere as a result of the introduction of a vacancy leads to noticeable changes in the TDOS curve, which indicates either a significant role of the atoms of the third coordination sphere or a significant redistribution of the interaction of d-orbitals of different symmetries of close neighbours. A correlation between the packing density, as well as the number of neighbours in the first coordination sphere, and the width of the energy band of gold monolayers has been established.

The role of negative ions on the Jeans instability in a complex plasma in the presence of nonthermal positive ions

2006 ◽  
Vol 13 (10) ◽  
pp. 102904 ◽  
Author(s):  
Banamali Roy ◽  
Susmita Sarkar ◽  
Manoranjan Khan ◽  
M. R. Gupta
Keyword(s):  
Negative Ions ◽  
Complex Plasma ◽  
Positive Ions ◽  
Jeans Instability

d Orbitals in the noble-gas dihalides

1970 ◽  
Vol 48 (17) ◽  
pp. 2695-2701 ◽  
Author(s):  
R. C. Catton ◽  
K. A. R. Mitchell
Keyword(s):  
Noble Gas ◽  
Valence Bond ◽  
Ionic Character ◽  
Orbital Exponent ◽  
Covalent Bonds ◽  
Model Calculations ◽  
Pair Bonds ◽  
Electron Repulsion Integrals ◽  
D Orbitals

Model calculations are reported for ArF2, KrF2, XeF2, ArCl2, KrCl2, and XeCl2. The approach is to compare the energies of a number of valence-bond structures for each molecule. The calculations use Slater-type radial functions and simplify the electron repulsion integrals with the Mulliken approximation. Energies are optimized by varying the d orbital exponent and a parameter which governs the ionic character of the covalent bonds. For all the molecules it is found that the structures such as (X—M+X− + X−M+—X) and X−M2+X−, which maintain the octet rule and exclude the use of d orbitals, are less stable than the structure X—M—X which implies localized electron-pair bonds based on pd hybrids at the noble-gas atom M.Approximate molecular wave functions are obtained from a configuration interaction calculation, and the general conclusion is that the valence-bond structures incorporating d orbitals become more important as the atomic number of the central atom increases. A preliminary study of the role of the [Formula: see text] orbital is also presented, but it seems this orbital contributes mainly as a polarization effect.

The role of negative ions in the growth of ionization and breakdown in N2O

Vacuum ◽  
1974 ◽  
Vol 24 (11-12) ◽  
pp. 609
Author(s):  
J. Dutton ◽  
F.M. Harris ◽  
D.B. Hughes
Keyword(s):  
Negative Ions
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