Many-body theory calculations of positron binding to parabenzoquinone

Fuente: arXiv
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Autores principales: Gregg, S. K., Hofierka, J., Cunningham, B., Green, D. G.
Formato: Preprint
Publicado: 2025
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author Gregg, S. K.
Hofierka, J.
Cunningham, B.
Green, D. G.
author_facet Gregg, S. K.
Hofierka, J.
Cunningham, B.
Green, D. G.
contents Positron binding in parabenzoquinone is studied using \textit{ab initio} many-body theory. The effects of electron-positron correlations including polarization, virtual positronium formation and positron-hole repulsion, as well as those of $π$ bonds, aromaticity, and lone electron pairs, are considered. The binding energy is calculated as 60$\pm$16 meV, considerably larger than the 0.0925 meV value inferred from recent scattering calculations of [G. Moreira and M. Bettega, {\emph{Eur.~Phys.~J.~D}} {\bf 78} (2024)], but substantially smaller than we find in benzene (148$\pm$26 meV). The positron contact density (lifetime) is calculated as 8.0$\times10^{-3}$ a.u. (2.48 ns), vs.~1.61$\times 10^{-2}$ a.u. (0.81 ns) in benzene. The decrease (increase) in binding (annihilation rate) in parabenzoquinone compared to benzene is ascribed to the loss of aromaticity: the electron density on the positive oxygen nuclei being relatively harder for the positron to probe compared to the aromatic rings in benzene.
format Preprint
id arxiv_https___arxiv_org_abs_2502_10327
institution arXiv
publishDate 2025
record_format arxiv
spellingShingle Many-body theory calculations of positron binding to parabenzoquinone
Gregg, S. K.
Hofierka, J.
Cunningham, B.
Green, D. G.
Chemical Physics
Atomic Physics
Computational Physics
Quantum Physics
Positron binding in parabenzoquinone is studied using \textit{ab initio} many-body theory. The effects of electron-positron correlations including polarization, virtual positronium formation and positron-hole repulsion, as well as those of $π$ bonds, aromaticity, and lone electron pairs, are considered. The binding energy is calculated as 60$\pm$16 meV, considerably larger than the 0.0925 meV value inferred from recent scattering calculations of [G. Moreira and M. Bettega, {\emph{Eur.~Phys.~J.~D}} {\bf 78} (2024)], but substantially smaller than we find in benzene (148$\pm$26 meV). The positron contact density (lifetime) is calculated as 8.0$\times10^{-3}$ a.u. (2.48 ns), vs.~1.61$\times 10^{-2}$ a.u. (0.81 ns) in benzene. The decrease (increase) in binding (annihilation rate) in parabenzoquinone compared to benzene is ascribed to the loss of aromaticity: the electron density on the positive oxygen nuclei being relatively harder for the positron to probe compared to the aromatic rings in benzene.
title Many-body theory calculations of positron binding to parabenzoquinone
topic Chemical Physics
Atomic Physics
Computational Physics
Quantum Physics
url https://arxiv.org/abs/2502.10327