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The spherical-solid model: An application to x-ray edges in Li, Na, and Al

Almbladh, Carl-Olof LU and von Barth, Ulf LU (1976) In Physical Review B 13(8). p.3307-3319
Abstract
In order to treat highly localized excitations in a solid a simple spherical model has been developed. The Coulomb potential from the nucleus at the site of the excitation is treated exactly, while the potentials from the surrounding sites are turned into pseudoion pontentials. Only the spherical average of these potentials is retained and separate self-consistent calculations for the ground state and for the excited state are made. These states are mistreated by the model but the difference accurately describes the large effects of polarization involved. The positions of the x-ray edges are obtained with an accuracy of 0.5 eV for singly ionized levels and 1 eV for doubly ionized levels. The phase shifts relevant to the Nozières-De... (More)
In order to treat highly localized excitations in a solid a simple spherical model has been developed. The Coulomb potential from the nucleus at the site of the excitation is treated exactly, while the potentials from the surrounding sites are turned into pseudoion pontentials. Only the spherical average of these potentials is retained and separate self-consistent calculations for the ground state and for the excited state are made. These states are mistreated by the model but the difference accurately describes the large effects of polarization involved. The positions of the x-ray edges are obtained with an accuracy of 0.5 eV for singly ionized levels and 1 eV for doubly ionized levels. The phase shifts relevant to the Nozières-De Dominicis theory of x-ray absorption and emission edges and x-ray photoemission line shapes are also calculated. We obtain a noticeable many-body enhancement of the L2,3 edge in Na while the many-body effect in Li and Al is negligible. Our exponents agree with those extracted from recent x-ray photoemission experiments, but they do not agree with those extracted from x-ray emission or absorption spectra. We argue that the exponents taken from the photoemission experiment are more reliable but no definite conclusion concerning the validity of the present many-body theory should be drawn until the experimental situation has become more clear. (Less)
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author
organization
publishing date
type
Contribution to journal
publication status
published
subject
in
Physical Review B
volume
13
issue
8
pages
3307 - 3319
publisher
American Physical Society
external identifiers
  • Scopus:0001658937
ISSN
1550-235X
language
English
LU publication?
yes
id
732a6836-3e9a-46e1-bd0d-e4fe6a2b31bf (old id 8772462)
date added to LUP
2016-02-27 01:20:31
date last changed
2016-04-16 12:19:25
@misc{732a6836-3e9a-46e1-bd0d-e4fe6a2b31bf,
  abstract     = {In order to treat highly localized excitations in a solid a simple spherical model has been developed. The Coulomb potential from the nucleus at the site of the excitation is treated exactly, while the potentials from the surrounding sites are turned into pseudoion pontentials. Only the spherical average of these potentials is retained and separate self-consistent calculations for the ground state and for the excited state are made. These states are mistreated by the model but the difference accurately describes the large effects of polarization involved. The positions of the x-ray edges are obtained with an accuracy of 0.5 eV for singly ionized levels and 1 eV for doubly ionized levels. The phase shifts relevant to the Nozières-De Dominicis theory of x-ray absorption and emission edges and x-ray photoemission line shapes are also calculated. We obtain a noticeable many-body enhancement of the L2,3 edge in Na while the many-body effect in Li and Al is negligible. Our exponents agree with those extracted from recent x-ray photoemission experiments, but they do not agree with those extracted from x-ray emission or absorption spectra. We argue that the exponents taken from the photoemission experiment are more reliable but no definite conclusion concerning the validity of the present many-body theory should be drawn until the experimental situation has become more clear.},
  author       = {Almbladh, Carl-Olof and von Barth, Ulf},
  issn         = {1550-235X},
  language     = {eng},
  number       = {8},
  pages        = {3307--3319},
  publisher    = {ARRAY(0x997ee98)},
  series       = {Physical Review B},
  title        = {The spherical-solid model: An application to x-ray edges in Li, Na, and Al},
  volume       = {13},
  year         = {1976},
}