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oai:figshare.com:article/32639070 2026-10-01T16:42:51Z portal_1172 item_type_8 month_year_10_2026

Many-body theory of positron interactions with molecules Jaroslav Hofierka (591945) PUREID: 552562309 Many-body theory positrons This work develops a many-body theory of positron–molecule interactions and its implementation in our state-of-the-art parallelised open-source C/C++ program EXCITON+.<br>Calculations of positron binding, elastic scattering, and direct annihilation in polyatomic molecules are presented. The strong positron-molecule correlations are accounted for via a diagrammatic description of the self-energy of the positron in the field of the molecule.<br><br>It is constructed by solving the Bethe-Salpeter equations for the two-body propagators in the positron-electron, positron-hole, and electron-hole channels. Positron binding to negative ions, atoms, and molecules in the fixed-nuclei approximation is studied. For positron binding to molecules, the approach [published in J. Hofierka, B. Cunningham, C. M. Rawlins, C. H. Patterson and D. G. Green, Nature 606, 688 (2022)]: (i) gives the first ab initio calculations in close agreement with data from over two decades of pioneering experiments; (ii) provides fundamental insight into the role of correlations including quantifying the role of virtual-positronium formation in enhancing binding in polar molecules and enabling binding in non-polars, and increasing annihilation rates by 2 to 3 orders of magnitude; and (iii) proposes a computationally less expensive approach to account for the important process of virtual-positronium formation, demonstrated by predicting binding energies in DNA nucleobases. 2026-10-01T16:42:51Z Text Thesis 10.17034/32639070.v1 https://figshare.com/articles/thesis/Many-body_theory_of_positron_interactions_with_molecules/32639070 All Rights Reserved