Low-energy (keV or less) antiprotons moving or scattering in ordinary matter is strongly affected by the interaction potential between the antiproton and the atoms. This interaction can be modeled by using potentials that have been obtained in quantum chemical calculations of the interaction between an antiproton and an atom with electron screening. To determine the interactions of antiprotons with any element, we here develop a universal antiproton-atom interaction potential. The potential is constructed by fitting a universal functional form to 14 pair-specific antiproton-atom potentials calculated with quantum chemical approaches and tested against three pair-specific potentials that were not part of the fit. We also report pair-specific screened antiproton-atom potentials for 17 elements, five of which are constructed in this work. By performing molecular dynamics simulations of the antiproton transmission through thin films, we show that the universal potential yields almost as good agreement with experiments as simulations carried out with the pair-specific potentials.

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• Interatomic & molecular potentials
• Antiprotons
• First-principles calculations
• Hartree-Fock methods
• Quantum chemistry methods