Electron-positron Car-Parrinello methods: self-consistent treatment of charge densities and ionic relaxations

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A1 Alkuperäisartikkeli tieteellisessä aikakauslehdessä
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Date

1995-10-15

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Department of Applied Physics

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Language

en

Pages

15
10947-10961

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PHYSICAL REVIEW LETTERS, Volume 52, issue 15

Abstract

A calculation method based on the two-component density-functional theory is presented for electron systems with a localized positron. Electron-ion and positron-ion interactions are described by norm-conserving pseudopotentials and full ionic potentials, respectively. The electron and positron densities are solved self-consistently using a plane-wave expansion for electron and a real-space grid method for positron wave functions, respectively. The forces on ions exerted by a positron trapped at an open-volume defect and the ensuing ionic relaxations are determined using first-principles methods. In the case of semiconductors, the self-consistent solution of electron and positron densities as well as the ionic positions are found to depend strongly on the treatment of the electron-positron correlation in constructing the effective potentials. We consider several approximations to the correlation energy while demonstrating the method by calculations for a positron trapped by a Ga vacancy in GaAs. Especially, the effects on the observable positron annihilation characteristics, i.e., positron lifetimes, core annihilation line shapes, and two-dimensional angular correlation maps are discussed.

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positron annihilation

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DOI

10.1103/PhysRevB.52.10947

Citation

Puska , M J , Seitsonen , A P & Nieminen , R M 1995 , ' Electron-positron Car-Parrinello methods: self-consistent treatment of charge densities and ionic relaxations ' , Physical Review Letters , vol. 52 , no. 15 , pp. 10947-10961 . https://doi.org/10.1103/PhysRevB.52.10947

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https://urn.fi/URN:NBN:fi:aalto-201805222593

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[article-cris] Perustieteiden korkeakoulu / SCI