Role of anharmonicity of atomic vibrations in formation of vacancies in rare-gas crystals

We investigate the potential energy curves of rare-gas dimers with various ranges and strengths of interparticle interactions (nuclear–electron, electron–electron, and nuclear–nuclear interactions).

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The role of halogen donors in discharge instability of rare-gas halide excimer lasers

Applied Physics B Photophysics and Laser Chemistry ◽

10.1007/bf00324953 ◽

1989 ◽

Vol 49 (6) ◽

pp. 535-540 ◽

Cited By ~ 6

Author(s):

D. Lo

Keyword(s):

Rare Gas ◽

Excimer Lasers

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X-ray diffraction study of the atomic interactions, anharmonic displacements and inner-crystal field in orthorhombic KNbO3

Acta Crystallographica Section B Structural Science Crystal Engineering and Materials ◽

10.1107/s2052520621006892 ◽

2021 ◽

Vol 77 (5) ◽

Author(s):

Adam I. Stash ◽

Ekaterina O. Terekhova ◽

Sergey A. Ivanov ◽

Vladimir G. Tsirelson

Keyword(s):

Diffraction Study ◽

Electron Density ◽

Ferroelectric Phase ◽

Ferroelectric Properties ◽

Structural Disorder ◽

Space Distribution ◽

X Ray Diffraction ◽

X Ray ◽

Atomic Vibrations

An X-ray diffraction study aimed at establishing the subtle details of the electron density and anharmonicity of the atomic vibrations in a stoichiometric monodomain single crystal of potassium niobate, KNbO3, has been conducted at room temperature (orthorhombic ferroelectric phase Amm2). The cation and anion displacements obtained from the experiment are weakly anharmonic without any manifestation of structural disorder. The chemical bond and interatomic interactions inside and between crystal substructures at the balance of intracrystalline forces are characterized in detail. The role of each of the ions in the formation of the ferroelectric phase was studied and the features of the electron-density deformation in the niobium and oxygen substructures, and the role of each of them in the occurrence of spontaneous polarization are established. The position-space distribution of electrostatic and quantum forces in KNbO3 is restored. It is emphasized that for the completeness of the analysis of the nature of the ferroelectric properties it is necessary to consider both static and kinetic electronic factors, which are of a quantum origin. The experimental results and theoretical estimations by the Kohn–Sham calculation with periodic boundary conditions are in reasonable agreement, thus indicating the physical significance of the findings of this study.

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Kinetics of electron capture by SF6 in solution

Canadian Journal of Chemistry ◽

10.1139/v77-296 ◽

1977 ◽

Vol 55 (11) ◽

pp. 2133-2143 ◽

Cited By ~ 10

Author(s):

James K. Baird

Keyword(s):

Long Range ◽

Electron Capture ◽

Liquid Hydrocarbon ◽

Rare Gas ◽

Polarization Force ◽

Dielectric Screening ◽

Solvent Molecules ◽

Kinetics Of ◽

Propane Butane

We present a theory of the rate constant for electron capture by SF6 when it is dissolved in liquid hydrocarbon and condensed rare gas solvents. The theory includes the effects of diffusion and solvation on the observed rate. Also included is the effect of the long-range polarization force acting between the electron and the SF6 molecule. The role of the solvent molecules in modifying this force is taken into account by use of a dielectric screening function. The theory is applied with semiquantitative success to electron capture data in the solvents: methane, ethane, propane, butane, n-pentane, neopentane, n-hexane, cyclohexane, isooctane, tetramethylsilane, argon, and xenon.

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