Full correlation single-particle positron potentials for a positron and a positronium interacting with atoms
| Autor: | Zubiaga, A., Tuomisto, F., Puska, M. |
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| Rok vydání: | 2013 |
| Předmět: | |
| Zdroj: | Phys. Rev. A 89, 052707 (2014) |
| Druh dokumentu: | Working Paper |
| DOI: | 10.1103/PhysRevA.89.052707 |
| Popis: | 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 Schr\"odinger 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. Comment: 10 pages, 2 tables, 5 figures |
| Databáze: | arXiv |
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