Electronic polarizabilities, ionic radii, and repulsive potential parameters for diatomic alkali halide molecules

1980 ◽  
Vol 58 (7) ◽  
pp. 950-956 ◽  
Author(s):  
Jai Shanker ◽  
H. B. Agrawal
Keyword(s):  
Alkali Halide ◽  
Dipole Moments ◽  
Inverse Power ◽  
Exponential Dependence ◽  
Molecular Constants ◽  
Repulsive Potential ◽  
Ionic Radii ◽  
Internuclear Distances ◽  
Potential Parameters ◽  
Level Analysis

The electronic polarizabilities of ions in diatomic alkali halide molecules calculated using the Seitz–Ruffa energy level analysis are found to agree closely with those recently estimated by Brumer and Karplus utilizing the exchange perturbation theory. A sensible test of these polarizabilities has been presented by calculating the molecular properties like dipole moments. Ionic radii for alkali and halogen ions appropriate to diatomic molecules are determined using the relation between size and effective nuclear charges. The radii thus evaluated are found to be nearly additive and reproduce the internuclear distances within about ± 0.10 Å for all the alkali halide molecules except for RbF and CsF. An analysis of interaction energies in alkali halide molecules is presented by adopting two potential forms for the repulsive energy showing, respectively, the inverse power dependence and exponential dependence on internuclear distance. The additivity of repulsive potential parameters is discussed in the light of recent investigations. The results for the molecular constants obtained from the exponential form are in much better agreement with experiment than those estimated from the inverse power form.

scholarly journals Modelling Cationic Diffusion in Nickel-Based Honeycomb Layered Tellurates using Vashishta-Rahman Interatomic Potential and Relevant Insights

2021 ◽  
Author(s):  
Kartik Sau ◽  
Tamio Ikeshoji ◽  
Godwill Mbiti Kanyolo ◽  
Titus Masese
Keyword(s):  
Performance Enhancement ◽  
Interatomic Potential ◽  
Theoretical Studies ◽  
Layered Oxides ◽  
Ionic Radii ◽  
Diffusion Channel ◽  
Exponential Increase ◽  
Potential Parameters ◽  
Insight Into

<b>Although the fascinatingly rich crystal chemistry of honeycomb layered oxides has been accredited as the propelling force behind their remarkable electrochemistry, the atomistic mechanisms surrounding their operations remain unexplored. Thus, herein, we present an extensive molecular dynamics study performed systematically using a refined set of inter-atomic potential parameters of <i>A</i><sub>2</sub>Ni<sub>2</sub>TeO<sub>6</sub> (where <i>A</i> = Li, Na, and K). We demonstrate the effectiveness of the Vashishta-Rahman form of the interatomic potential in reproducing various structural and transport properties of this promising class of materials and predict an exponential increase in cationic diffusion with larger interlayer distances. The simulations further demonstrate the correlation between broadened inter-layer (inter-slab) distances associated with the larger ionic radii of K and Na compared to Li and the enhanced cationic conduction exhibited in K<sub>2</sub>Ni<sub>2</sub>TeO<sub>6</sub> and Na<sub>2</sub>Ni<sub>2</sub>TeO<sub>6</sub> relative to Li<sub>2</sub>Ni<sub>2</sub>TeO<sub>6</sub>. Whence, our findings connect lower potential energy barriers, favourable cationic paths and wider bottleneck size along the cationic diffusion channel within frameworks (comprised of larger mobile cations) to the improved cationic diffusion experimentally observed in honeycomb layered oxides. Furthermore, we explicitly study the role of inter-layer distance and cationic size in cationic diffusion. Our theoretical studies reveal the dominance of inter-layer distance over cationic size, a crucial insight into the further performance enhancement of honeycomb layered oxides.</b><br>

scholarly journals Modelling Cationic Diffusion in Nickel-Based Honeycomb Layered Tellurates using Vashishta-Rahman Interatomic Potential and Relevant Insights

2021 ◽  
Author(s):  
Kartik Sau ◽  
Tamio Ikeshoji ◽  
Godwill Mbiti Kanyolo ◽  
Titus Masese
Keyword(s):  
Performance Enhancement ◽  
Interatomic Potential ◽  
Layered Oxides ◽  
Ionic Radii ◽  
Diffusion Channel ◽  
Atomic Potential ◽  
Exponential Increase ◽  
Potential Parameters ◽  
Insight Into

<b>Although the fascinatingly rich crystal chemistry of honeycomb layered oxides has been accredited as the propelling force behind their remarkable electrochemistry, the atomistic mechanisms surrounding their operations remain unexplored. Thus, herein, we present an extensive molecular dynamics study performed systematically using a reliable set of inter-atomic potential parameters of </b><i>A</i><sub>2</sub><b>Ni</b><sub>2</sub><b>TeO</b><sub>6</sub><b> (where </b><i>A</i><b> = Li, Na, and K). We demonstrate the effectiveness of the Vashishta-Rahman form of the inter-atomic potential in reproducing various structural and transport properties of this promising class of materials and predict an exponential increase in cationic diffusion with larger inter-layer distances. The simulations demonstrate the correlation between broadened inter-layer (inter-slab) distances associated with the larger ionic radii of K and Na compared to Li and the enhanced cationic conduction exhibited in K</b><sub>2</sub><b>Ni</b><sub>2</sub><b>TeO</b><sub>6</sub><b> and Na</b><sub>2</sub><b>Ni</b><sub>2</sub><b>TeO</b><sub>6</sub><b> relative to Li</b><sub>2</sub><b>Ni</b><sub>2</sub><b>TeO</b><sub>6</sub><b>. Whence, our findings connect lower potential energy barriers, favourable cationic paths and wider bottleneck size along the cationic diffusion channel within frameworks (comprised of larger mobile cations) to the improved cationic diffusion experimentally observed in honeycomb layered oxides. Furthermore, we elucidate the role of inter-layer distance and cationic size in cationic diffusion. Our theoretical studies reveal the dominance of inter-layer distance over cationic size, a crucial insight into the further performance enhancement of honeycomb layered oxides.</b><br>

An Exponential Function for Repulsive Interaction Energy Term I. Application to Alkali Halides

1974 ◽  
Vol 29 (11) ◽  
pp. 1601-1607
Author(s):  
K. D. Misra ◽  
V. K. Dixit ◽  
M. N. Sharma
Keyword(s):  
Equation Of State ◽  
Alkali Halide ◽  
Alkali Halides ◽  
Good Choice ◽  
Repulsive Interaction ◽  
Energy Term ◽  
Energy Functions ◽  
Potential Energy Functions ◽  
Alkali Halide Crystals ◽  
Potential Parameters

The appropriateness of a suitably modified Varshni-Shukla potential has been tested for a series of alkali halide crystals by determining the numerical values of the potential parameters involved, using Hildebrand’s equation of state and thereby computing a few lattice properties. Comparison between the different sets of theoretical and experimental results infers that the present theoretical values exhibit an improvement over those of other workers, using a similar approach but with different potential energy functions. It is concluded that the modified V -S potential function is a good choice for explaining the behaviour of alkali halide lattices.

Secondary ion mass spectrometry of metal halides. 3. Ionic radii effects in alkali halide clusters

1983 ◽  
Vol 87 (18) ◽  
pp. 3441-3445 ◽  
Author(s):  
Thomas M. Barlak ◽  
Joseph E. Campana ◽  
Jeffrey R. Wyatt ◽  
Richard J. Colton
Keyword(s):  
Mass Spectrometry ◽  
Alkali Halide ◽  
Secondary Ion Mass Spectrometry ◽  
Metal Halides ◽  
Ionic Radii ◽  
Ion Mass Spectrometry ◽  
Secondary Ion

scholarly journals An equation to calculate internuclear distances of covalent, ionic and metallic lattices

2015 ◽  
Vol 17 (5) ◽  
pp. 3355-3369 ◽  
Author(s):  
Peter F. Lang ◽  
Barry C. Smith
Keyword(s):  
Metallic Structure ◽  
Ionic Radii ◽  
Internuclear Distances ◽  
Simple Equations

Simple equations calculating accurately internuclear distances of ionic (radii derived from metallic structure), covalent and metallic lattices are proposed.

scholarly journals Role of Interlayer Distance on Cationic Diffusion of Nickel-Based Honeycomb Layered Tellurates

2021 ◽  
Author(s):  
Kartik Sau ◽  
Tamio Ikeshoji ◽  
Godwill Mbiti Kanyolo ◽  
Titus Masese
Keyword(s):  
Molecular Dynamics ◽  
Transport Properties ◽  
Crystal Chemistry ◽  
Interatomic Potential ◽  
Layered Oxides ◽  
Ionic Radii ◽  
Diffusion Channel ◽  
Exponential Increase ◽  
Potential Parameters

<b>Although the fascinatingly rich crystal chemistry of honeycomb layered oxides has been accredited as the propelling force behind their remarkable electrochemistry, the atomistic mechanisms surrounding their operations remain unexplored. Thus, herein, we present an extensive molecular dynamics study performed systematically using a refined set of inter-atomic potential parameters of <i>A</i><sub>2</sub>Ni<sub>2</sub>TeO<sub>6</sub> (where <i>A</i> = Li, Na, and K). We demonstrate the effectiveness of the Vashishta-Rahman form of the interatomic potential in reproducing various structural and transport properties of this promising class of materials and predict an exponential increase in cationic diffusion with larger interlayer distances. The simulations further demonstrate the correlation between broadened inter-layer (inter-slab) distances associated with the larger ionic radii of K and Na compared to Li and the enhanced cationic conduction exhibited in K<sub>2</sub>Ni<sub>2</sub>TeO<sub>6</sub> and Na<sub>2</sub>Ni<sub>2</sub>TeO<sub>6</sub> relative to Li<sub>2</sub>Ni<sub>2</sub>TeO<sub>6</sub>. Whence, our findings connect a wider bottleneck along the cationic diffusion channel within frameworks comprised of larger mobile cations to the improved cationic diffusion experimentally observed in honeycomb layered oxides. </b>

Structure and Bonding of KrClF: Intermolecular Force Fields in Van Der Waals Molecules

1975 ◽  
Vol 53 (19) ◽  
pp. 2007-2015 ◽  
Author(s):  
Stewart E. Novick ◽  
Stephen J. Harris ◽  
Kenneth C. Janda ◽  
William Klemperer
Keyword(s):  
Molecular Beam ◽  
Dipole Moments ◽  
Van Der Waals ◽  
Equilibrium Structure ◽  
Microwave Spectrum ◽  
Resonance Spectroscopy ◽  
Electric Resonance ◽  
Molecular Constants ◽  
Van Der Waals Molecules ◽  
Coupling Terms

The radio frequency and microwave spectrum of KrClF has been measured by molecular beam electric resonance spectroscopy. The molecular constants for the major isotope (84Kr35ClF) are:[Formula: see text]The atomic arrangement is Kr—Cl—F with a linear equilibrium structure and the vibrationally averaged 84Kr—35Cl distance is 3.3884 Å. The molecular structure is very similar to that of ArClF, previously studied in this laboratory. Vibrational frequencies, force constants, estimated well depths, dipole moments, and distances in the two molecules are compared. Molecular constants of the four KrClF isotopes studied are used to derive a vibrational force field for the molecule, including anharmonic and bend–stretch coupling terms. A brief summary of the four linear van der Waals molecules studied spectroscopically in this laboratory is presented, along with a simple and structurally predictive model of the van der Waals bond.

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