Discrete-basis-set calculation fore-N2scattering cross sections in the static-exchange approximation

Calculations are reported for low-energy $e$-${\mathrm{N}}_2$ scattering cross sections in the static-exchange approximation. Our approach involves solving the Lippman-Schwinger equation for the transition operator in a subspace of Gaussian functions. A new feature of the method is the analytical evaluation of matrix elements of the free-particle Green's function. Another development is the use of an analytical transformation to obtain single-center expansion coefficients for the scattering amplitude from our multicenter discrete-basis-set representation of the $T$ matrix. We present results for the total elastic and rotational excitation cross sections, and the momentum-transfer cross section, for incident electron energies from 0.5 to 10 eV. Comparison is made with other theoretical results and experimental data.