Full correlation single-particle positron potentials for a positron and a positronium interacting with atoms

Abstract

In this work we define single-particle potentials for a positron and a positronium atom interacting with light atoms (H, He, Li and Be) by inverting a single-particle Schrödinger equation. For this purpose, we use accurate energies and positron densities obtained from the many-body wavefunction of the corresponding positronic systems. The introduced potentials describe the exact correlations for the calculated systems including the formation of a positronium atom. We show that the scattering lengths and the low-energy s-wave phase shifts from accurate many-body calculations are well accounted for by the introduced potential. We also calculate self-consistent two-component density-functional theory positron potentials and densities for the bound positronic systems within the local density approximation. They are in a very good agreement with the many-body results, provided that the finite-positron-density electron-positron correlation potential is used, and they can also describe systems comprising a positronium atom. We argue that the introduced single-particle positron potentials defined for single molecules are transferable to the condensed phase when the inter-molecular interactions are weak. When this condition is fulfilled, the total positron potential can be constructed in a good approximation as the superposition of the molecular potentials.

10 pages, 2 tables, 5 figures

References in corpus (3)

• Quantum ESPRESSO: a modular and open-source software project for quantum simulations of materials
• Quantum Monte Carlo Study of a Positron in an Electron Gas
• Matter-positronium interaction: An exact diagonalization study of the He atom - positronium system

Cited by in corpus (5)

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• Quantifying errors of the electron-proton/muon correlation functionals through the Kohn-Sham inversion of a two-component model system
• Time-Dependent Multi-Component Density Functional Theory for Coupled Electron-Positron Dynamics
• Atomic Confinement Potentials and the Generation of Numerical Atomic Orbitals
• Exotic Harmonium Model: Exploring Correlation Effects of Attractive Coulomb Interaction