Atomic Collision Theory

Atomic collisions involve interactions between electrons, positrons, photons, (anti)protons, atoms, ions, molecules and surfaces. They go on all around and inside us. The aim of the project is to increase our understanding of ever more complicated collision systems of importance to both fundamental science and industry. The investigators have developed a world-leading computational theory for the purpose. It is constantly being extended to ever more complicated targets and projectiles. The recent implementation of diatomic molecules means that this area is about to undergo revolutionary progress, as soon as sufficient computational power is made available. Furthermore, recent developments in hadron (cancer) therapy, and the study of high energy events in the universe such as solar wind or supernova, require the calculation of charge exchange processes that only our theory can accurately provide.

Principal investigator

Igor Bray
Magnifying glass

Area of science

Applied Science, Chemistry, Physics

Systems used


Applications used

Partner Institution: Curtin| Project Code: d35

The Challenge

The ever growing complexity of collision systems in terms of complexity of target e.g. molecule structure needs to be computationally modeled in a way that allows for a subsequent collision calculation to be performed.

The Solution

We utilise large-scale Laguerre bases to expand the target wavefunctions which are then used to form momentum-space close-coupling equations.

The Outcome

Super-computing has been a critical infrastructure of our field since its inception forty years ago. No progress would be possible without it.

List of Publications

Twenty publications have arisen during 2018, please see, or available as pdf at

Figure 1. e-H.pdf: Electron impact ionisation cross section and spin asymmetry of atomic hydrogen. From Bray et al, Phys. Rev. Lett. 121, 203401 (2018)
Figure 2. p-H.pdf: Positron impact ionisation and positronium formation of atomic hydrogen. From Bray et al, Phys. Rev. Lett. 121, 203401 (2018)