Speaker
Description
Positron interactions with atoms and molecules are characterised by strong many-body correlations including polarisation of the electron cloud by the positron, screening of the electron-positron Coulomb interaction, and the process of virtual-positronium formation (in which a molecular electron temporarily tunnels to the positron) [1]. The correlations significantly enhance annihilation rates, modify scattering, and enable positron binding to atoms and molecules.
Recently our group developed an ab initio many-body theory approach to the calculation of positron binding in polyatomic molecules [1]. Here, we apply it to the picolines, the three isomers of methylpyridine (CH3C5H4N).
Calculated positron binding energies and contact densities will be presented and compared to experiments where available. The role of the correlations, and the effect of the relative geometry of the nitrogen and methyl group will be examined.
[1] J. Hofierka, ..., D. G. Green, Nature 606, 688 (2022).
