Schwinger multichannel study of theΠg2shape resonance inN2

We report the results of a study on electron-target correlations in the ${}_{}{}^2{}_{}{}^{}\mathrm{\Pi }_{\mathrm{g}}^{}{}_{}{}^{}$ shape resonance of elastic e-${\mathrm{N}}_2$ scattering, using the Schwinger multichannel formulation. The effects of basis set, orbital representation, and closed-channel configurations are delineated. The different roles of radial and angular correlations are compared. Our results are in good agreement with a recent calculation by Schneider and Collins [Phys. Rev. A 30, 95 (1984)] using the linear algebraic-optical potential method whereas calculations using radial correlations alone agree well with previous calculations based on a variety of different approaches.