scholarly journals New Scale of the Ionic Character of the Chemical Bond Using Multiconfiguration SCF Wave Functions

1981 ◽  
Vol 54 (4) ◽  
pp. 967-970 ◽  
Author(s):  
Kazuhiro Ishida ◽  
Shuichi Kadowaki ◽  
Teijiro Yonezawa
Keyword(s):  
Chemical Bond ◽  
Wave Functions ◽  
Ionic Character

Hyperfine measurements in the X and B electronic states of I35,37Cl: Probing the ionic character of the chemical bond

1994 ◽  
Vol 101 (9) ◽  
pp. 7221-7229 ◽  
Author(s):  
Timothy J. Slotterback ◽  
Simon G. Clement ◽  
Kenneth C. Janda ◽  
Colin M. Western
Keyword(s):  
Chemical Bond ◽  
Electronic States ◽  
Ionic Character

scholarly journals Chlorine NQR and Phase Transitions in NOCl

1996 ◽  
Vol 51 (5-6) ◽  
pp. 736-738 ◽  
Author(s):  
J. Pirnat ◽  
Z. Trontelj ◽  
H. Borrmann
Keyword(s):  
Phase Transition ◽  
Phase Transitions ◽  
Transition Temperature ◽  
Chemical Bond ◽  
Thermal Hysteresis ◽  
Ionic Character ◽  
Nitrosyl Chloride

Abstract Chlorine NQR studies of solid nitrosyl chloride NOCl at temperatures below 200 K were undertaken. They indicate an ionic character of the N-Cl chemical bond and confirm the phase transition near 140 K. Thermal hysteresis of the transition temperature was observed.

Optimization of the Choice of Technological Methods for Nanomodification of Natural Aluminosilicates through the Parameters of the Element-Oxygen Chemical Bond

2021 ◽  
Vol 887 ◽  
pp. 201-206
Author(s):  
O.S. Sirotkin ◽  
Artem E. Buntin
Keyword(s):  
Chemical Bond ◽  
Thermal Activation ◽  
Aqueous Suspension ◽  
Oxide Nanoparticles ◽  
Ionic Character ◽  
Covalent Character ◽  
Aluminum Oxide Nanoparticles ◽  
Isothermal Exposure ◽  
Quantitative Characteristics ◽  
Technological Methods

The paper shows the possibility of using such quantitative characteristics of the element-oxygen chemical bond as the covalent character, metallic character and ionic character in substances to select a set of technological methods and develop a technology for nanomodification of natural bentonite aluminosilicates. The research results showed that thermal activation of bentonite at 200, 300, 380 and 400 °C with different modes of isothermal exposure (15, 30, 60, 120 minutes) does not significantly affect the efficiency of its modification with silicon (SS) and aluminum (AS) oxide nanoparticles, estimated by the increment of the compressive strength and the adsorption index for methylene blue. Obtaining a 46 % aqueous suspension of bentonite and modifying it with silicon and aluminum oxide nanoparticles followed by ultrasonic treatment after standing decreases the particle size by more than 4 times, which is a promising technological solution for improving the performance properties of ceramics, molding mixtures, adsorbents and other materials based on bentonite from various deposits.

Soil Minerals

2016 ◽  
Author(s):  
Garrison Sposito
Keyword(s):  
Chemical Bond ◽  
Ionic Radius ◽  
Chemical Elements ◽  
Ionic Character ◽  
Soil Minerals ◽  
Covalent Bonds ◽  
Atomic Structures ◽  
Spatial Configurations ◽  
Ionic Bonds ◽  
Electron Clouds

The chemical elements in soil minerals occur typically as charged species arranged in spatial configurations held together by ionic bonds. Ionic bonds involve atoms that retain their unique “electron clouds” and, therefore, they are weaker than covalent bonds, which involve significant mixing of the electron clouds of the bonding atoms, leading to the electron sharing that makes covalent bonds stronger. However, ionic and covalent bonds are idealizations that real chemical bonds only approximate. A real chemical bond shows some degree of ionic character, which maintains the electronic identity of the bonding partners, and some degree of electron sharing, which blurs their electronic identity. The Si—O bond, for example, is said to be an even partition between ionic and covalent character, and the Al—O bond is thought to be about 40% covalent and 60% ionic. Aluminum, however, is exceptional. Almost all the metal–oxygen bonds that occur in soil minerals are ionic. For example, Mg—O and Ca—O bonds are considered to be 75% to 80% ionic whereas Na—O and K—O bonds are 80% to 85% ionic. Covalence thus plays a minor role in determining the atomic structures of soil minerals, aside from the important feature that Si—O bonds, being 50% covalent, impart mineral resistance to weathering, as discussed in Section 1.3. Given this perspective on bonding, the two most important properties of the chemical elements in soil minerals should be their ionic valence and radius. Valence is the ratio of the electric charge on an ionic species to the charge on the proton. Ionic radius is a less direct concept, because the radius of a single ion cannot be measured. Accordingly, ionic radius is a defined quantity based on the following three assumptions: (1) the radius of the bivalent oxygen ion (O2-)in all minerals is 0.140 nm, (2) the sum of radii of the cation and anion participating in a chemical bond equals the measured interatomic distance between the two, and (3) the ionic radius has the same value in all mineral structures containing an ion with a given coordination number (CN).

Density functionals and chemical bond, diatomic molecules

1989 ◽  
Vol 86 ◽  
pp. 853-859 ◽  
Author(s):  
Federico Moscardó ◽  
José Pérez-Jordá ◽  
Emilio San-Fabián
Keyword(s):  
Chemical Bond ◽  
Diatomic Molecules ◽  
Density Functionals

Magnetotunneling spectroscopy imaging of electron wave functions in self-assembled InAs quantum dots

2001 ◽  
Vol 171 (12) ◽  
pp. 1365
Author(s):  
E.E. Vdovin ◽  
Yu.N. Khanin ◽  
Yu.V. Dubrovskii ◽  
A. Veretennikov ◽  
A. Levin ◽  
...  
Keyword(s):  
Quantum Dots ◽  
Wave Functions ◽  
Electron Wave ◽  
Inas Quantum Dots ◽  
Self Assembled
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