Positron scattering by molecular nitrogen

Elastic momentum transfer and rotational excitation cross sections have been calculated for positron scattering by nitrogen molecules. The potential describing the interaction between the molecule and the positron consists of static and distortion contributions. The latter is of the Temkin type and results are presented for positron scattering by neon and argon, as well as molecular nitrogen, to show that this approximation may be qualitatively correct for positron energies greater than 2 eV. Wavefunctions and potentials are of single-centre form and the associated convergence problems are fully discussed.