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Enhancement factors for positron annihilation studies

Mitroy, J and Barbiellini, B (2002). Enhancement factors for positron annihilation studies. Physical Review B (Condensed Matter and Materials Physics),65(23):235103.

Document type: Journal Article
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Title Enhancement factors for positron annihilation studies
Author Mitroy, J
Barbiellini, B
Journal Name Physical Review B (Condensed Matter and Materials Physics)
Publication Date 2002
Volume Number 65
Issue Number 23
ISSN 1550-235X   (check CDU catalogue open catalogue search in new window)
Start Page 235103
Total Pages 7
Place of Publication College Park, Maryland, US
Publisher American Physical Society
Field of Research MATHEMATICAL SCIENCES
PHYSICAL SCIENCES
ENGINEERING
HERDC Category C1 - Journal Article (DEST)
Abstract Electron and positron densities for a number of positron binding atoms and ions are used to benchmark methods used to compute positron annihilation rates in solids. The electron and positron densities from ab initio calculations are multiplied by some commonly used enhancement factors and integrated to give the annihilation rate. These are then compared with the close to exact annihilation rate calculation using the fully correlated positronic atom wave functions. The results reveal deficiencies in the one-component local-density approximation (LDA) and the Boronski-Nieminen two-component LDA. A simple modification of the one-component LDA leads to an enhancement factor that predicts annihilation rates more reliably for some positronic systems with a minimal increase in complexity. An approach based on an existing version of the generalized gradient approximation tends to underestimate the annihilation rate with the valence electrons.
Keywords stochastic variational method
density-functional theory
few-body problems
configuration-interaction
gradient-correction
wave-functions
bound-states
binding
atoms
solids
DOI http://dx.doi.org/10.1103/PhysRevB.65.235103   (check subscription with CDU E-Gateway service for CDU Staff and Students  check subscription with CDU E-Gateway in new window)
Additional Notes Print ISSN: 1098-0121
 
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Created: Fri, 12 Sep 2008, 08:35:25 CST by Administrator