Open AccessPositronium collisions with atoms and molecules
Author(s) -
R. S. Wilde,
I. I. Fabrikant
Publication year - 2020
Publication title -
journal of physics. conference series
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.21
H-Index - 85
eISSN - 1742-6596
pISSN - 1742-6588
DOI - 10.1088/1742-6596/1412/5/052011
Subject(s) - pseudopotential , positronium , scattering , atomic physics , orthogonality , ionization , electron scattering , electron , ab initio , chemistry , wave function , ab initio quantum chemistry methods , molecule , molecular physics , physics , quantum mechanics , positron , ion , geometry , mathematics , organic chemistry
We describe recent theoretical efforts to explain the observed similarity between electron and positronium (Ps) scattering with both atoms and molecules. In order to perform these calculations at a more ab initio level we have developed a Free Electron Gas (FEG) approximation to the exchange and correlation potentials similar to that used in electron-molecule scattering. The FEG results give good agreement with experiment above the Ps ionization threshold and exhibit resonance features below the threshold. To take account of the effect of orthogonality between the scattered electron and the target wavefunctions we have used an orthogonalizing pseudopotential (OPP). The FEG plus OPP results give good agreement with experiment for Ps-rare-gas scattering. Preliminary results for Ps-H 2 scattering also agree well with experiment and demonstrate the importance of including orthogonality for scattering below the Ps ionization threshold.