Binding energies and wave functions of Wannier excitons in uniaxial crystals—A modified perturbation approach II. Applications

1975 ◽  
Vol 67 (2) ◽  
pp. 477-485 ◽  
Author(s):  
B. Gerlach ◽  
J. Pollmann
Keyword(s):  
Binding Energies ◽  
Wave Functions ◽  
Perturbation Approach

The binding energies of atomic nuclei III. Nuclear forces and the ground state of oxygen 16

1959 ◽  
Vol 253 (1273) ◽  
pp. 186-198 ◽  
Keyword(s):  
Binding Energy ◽  
Electron Scattering ◽  
Ground State ◽  
Binding Energies ◽  
Wave Functions ◽  
Unperturbed System ◽  
Core Radius ◽  
Nuclear Forces ◽  
Potential Core ◽  
Atomic Nuclei

The r. m. s. radius and the binding energy of oxygen 16 are calculated for several different internueleon potentials. These potentials all fit the low-energy data for two nucleons, they have hard cores of differing radii, and they include the Gammel-Thaler potential (core radius 0·4 fermi). The calculated r. m. s. radii range from 1·5 f for a potential with core radius 0·2 f to 2·0 f for a core radius 0·6 f. The value obtained from electron scattering experiments is 2·65 f. The calculated binding energies range from 256 MeV for a core radius 0·2 f to 118 MeV for core 0·5 f. The experimental value of binding energy is 127·3 MeV. The 25% discrepancy in the calculated r. m. s. radius may be due to the limitations of harmonic oscillator wave functions used in the unperturbed system.

scholarly journals Universality of excited three-body bound states in one dimension

2021 ◽  
Author(s):  
Lucas Happ ◽  
Matthias Zimmermann ◽  
Maxim A Efremov
Keyword(s):  
Excited States ◽  
Bound States ◽  
Space Dimension ◽  
Binding Energies ◽  
Wave Functions ◽  
One Dimension ◽  
Strong Indication ◽  
Body System ◽  
Weakly Bound ◽  
Three Body

Abstract We study a heavy-heavy-light three-body system confined to one space dimension in the regime where an excited state in the heavy-light subsystems becomes weakly bound. The associated two-body system is characterized by (i) the structure of the weakly-bound excited heavy-light state and (ii) the presence of deeply-bound heavy-light states. The consequences of these aspects for the behavior of the three-body system are analyzed. We find a strong indication for universal behavior of both three-body binding energies and wave functions for different weakly-bound excited states in the heavy-light subsystems.

Low-energy pion photoproduction from p-shell nuclei

1990 ◽  
Vol 68 (11) ◽  
pp. 1270-1278 ◽  
Author(s):  
C. Bennhold ◽  
L. Tiator ◽  
L. E. Wright
Keyword(s):  
Form Factors ◽  
Pion Photoproduction ◽  
Binding Energies ◽  
Wave Functions ◽  
Low Energy ◽  
Delta Resonance ◽  
Transverse Electromagnetic ◽  
Coulomb Effects ◽  
Correction Terms ◽  
Space Approach

Low-energy pion photoproduction off 6Li, 10B, and 14N has been reinvestigated in a DWIA framework that includes a number of improvements neglected in previous analyses. The production operator is based on Feynman diagrams and includes correction terms of order p2/M2 and higher. An s-channel delta resonance term is included with both longitudinal and transverse electromagnetic couplings. Rather than using on harmonic oscillator for the nucleon orbitals we employ Woods–Saxon wave functions that have been adjusted to fit electron-scattering form factors and single-particle binding energies. Furthermore, we include the Coulomb potential without approximation in our momentum-space approach. Using more realistic wave functions and including corrections to the production amplitude that have been neglected before leads to considerable improvement in the case of 10B and 14N when compared with existing data. The Coulomb effects are shown to change the cross section by about 30% close to threshold but are negligible at higher energies.

The binding energies of s-shell nuclei

1969 ◽  
Vol 47 (24) ◽  
pp. 2825-2834 ◽  
Author(s):  
J. Law ◽  
R. K. Bhaduri
Keyword(s):  
Binding Energy ◽  
Long Range ◽  
Hard Core ◽  
Nucleon Nucleon ◽  
Interference Term ◽  
Binding Energies ◽  
Wave Functions ◽  
A Value ◽  
Range Part ◽  
Central Forces

We have calculated the binding energies of 4He and 3H with soft- and hard-core nucleon–nucleon potentials. With central forces, using harmonic-oscillator wave functions, we find that accurate results can be obtained by taking only the long-range part of the potential and its second-order perturbative term. When tensor forces are present, the long-range interference term is also included in the calculation. In this case, the method is not accurate and underbinds these nuclei by about 1 MeV per particle. Ignoring Coulomb forces, our method yields a value of 18.5 MeV for the binding energy of 4He with the Hamada–Johnston potential.

scholarly journals Multi-reference Approach to the Computation of Double-Core-Hole Spectra

2021 ◽  
Author(s):  
Bruno Nunes Cabral Tenorio ◽  
Piero Decleva ◽  
Sonia Coriani
Keyword(s):  
Small Molecules ◽  
Ground State ◽  
Binding Energies ◽  
Wave Functions ◽  
Correlation Effects ◽  
Core Hole ◽  
Active Space ◽  
Consistent Field ◽  
Self Consistent ◽  
Self Consistent Field

Double-Core Hole (DCH) states of small molecules are assessed with the restricted<br>active space self-consistent field (RASSCF) and multi-state restricted active space perturbation<br>theory of second order (MS-RASPT2) approximations. To ensure an unbiased<br>description of the relaxation and correlation effects on the DCH states, the neutral<br>ground state and DCH wave functions are optimized separately, whereas the spectral<br>intensities are computed with a biorthonormalized set of molecular orbitals within the<br>state-interaction (SI) approximation. Accurate shake-up satellites binding energies and<br>intensities of double-core-ionized states (K<sup>-2</sup>) are obtained for H<sub>2</sub>O, N<sub>2</sub>, CO and C<sub>2</sub>H<sub>2n</sub><br>(n=1–3). The results are analyzed in details and show excellent agreement with recent<br>experimental data.

The use of Gaussian (exponential quadratic) wave functions in molecular problems. II. Wave functions for the ground states of the hydrogen atom and of the hydrogen molecule

1960 ◽  
Vol 258 (1294) ◽  
pp. 421-430 ◽  
Keyword(s):  
Hydrogen Atom ◽  
Quadratic Form ◽  
Hydrogen Molecule ◽  
Ground States ◽  
Cylindrical Symmetry ◽  
Binding Energies ◽  
Wave Functions ◽  
Electronic Wave ◽  
Electronic Wave Functions ◽  
Independent Parameters

The results reported in this paper constitute a first examination of the use of Gaussian wave functions with correlation as approximations to electronic wave functions. Functions of the form Σ k = n k =1 C k exp ( – Q k ), where C k is a constant and Q k is a quadratic form corresponding to orbitals with cylindrical symmetry, variable centres and with correlation, are used for the hydrogen molecule. Binding energies of 4∙30, 4∙42, 4∙52 and 4∙58 eV are obtained with functions containing, respectively, 26, 35, 53 and 71 independent parameters. The accuracy of the results and the moderate computing times suggest that there is considerable scope for wave functions of this type. For the hydrogen atom, approximations to the 1 s -orbital in terms of Σ k = n k =1 C k exp ( – a k r 2 ) are given for n = 3, 4, 5, 6 and 8.

scholarly journals Dielectrically Confined Excitons and Polaritons in Natural Superlattices -Perovskite Lead Iodide Semiconductors

1993 ◽  
Vol 328 ◽  
Author(s):  
N. A. Gippius ◽  
E. A. Muljarov ◽  
S. G. Tikhodeev ◽  
T. Ishihara ◽  
L. V. KELDYSH
Keyword(s):  
Experimental Data ◽  
Strong Dependence ◽  
Binding Energies ◽  
Dielectric Constants ◽  
Wave Functions ◽  
Reflection Spectra ◽  
Lead Iodide ◽  
Superlattice Structure ◽  
Insulator Layers ◽  
Excitonic Effects

ABSTRACTA large class of new layered semiconductors — lead iodide compounds — is of great interest because of possible optoelectronic applications due to pronounced excitonic effects. These compounds may be regarded as naturally grown semiconductor/insulator superlat-tices, with perovskite lead iodide (semiconductor) layers sandwiched by alkylammonium (insulator) layers. Exciton binding energies and oscillator strength in these structures are enhanced due to the so-called “dielectric confinement” caused by large difference between dielectric constants of adjoining layers. The binding energies, wave functions,& diamagnetic coefficient of excitons in these naturally grown superlattices are calculated with allowance for the image potential and the superlattice structure of the compounds. The localization of excitons in lead iodide layers causes also a strong dependence of a polariton spike in reflection spectra on the polarization of electromagnetic wave. The results obtained are in agreement with the experimental data.

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