POLARIZATION POTENTIALS FOR POSITRON-MOLECULE SCATTERING PROCESSES

A new form of a local, model polarisation-correlation potential obtain ed via Density Functional Theory (DFT) is proposed for the treatment o f positron scattering from H-2 and N-2 molecules at energies below the threshold of positronium formation. The derivation of the potential i s briefly discussed and its relative importance for the elastic channe ls of the scattering process is analysed in detail. Final elastic cros s sections, rotationally summed, are compared with experiments and wit h existing theoretical results. They are found to agree reasonably wel l with measurements and suggest the present model as a useful, and sim ple, method for treating short-range correlation forces in positron sc attering calculations for molecular systems.