A simple method for evaluating low-energy electron-molecule scattering cross sections using discrete basis functions?

We present a simple, approximate method for calculating low-energy electronmolecule scattering cross sections using only the results of a basis set diagonalization of the molecular Hamiltonian. The method is based on the approximate conservation of orbital angular momentum in collisions between slow electrons and molecules lacking a permanent dipole moment (low I spoiling). Results are presented for e--H, and e--N, in the static-exchange approximation.