Ab initio calculations of 0.01–10 eV collisions of positrons with fullerene ${\text{C}}_{20}$ are performed using a single-center expansion of the total wave function and a model potential to represent the positron-molecule interaction. Total elastic cross sections and eigenphase sums are generated and analyzed, while bound states and possible long-lifetime scattering resonances are explored, particularly those which are found to reside within the cage structure defined by the carbon atoms of the cluster.

• Received 20 June 2007

DOI:https://doi.org/10.1103/PhysRevA.78.012706