Electron–molecule scattering data, observed experimentally or computed with methodology available as of 1980, was reviewed in detail by Lane [215]. If there were no nuclear motion, electron–molecule scattering would differ from electron–atom scattering only because of the loss of spherical symmetry and because of the presence of multiple Coulomb potentials due to the atomic nuclei. This is already a formidable challenge to theory, exemplified by the qualitative increase in computational difficulty and complexity between atomic theory and molecular theory for electronic bound states. While bound-state molecular computational methods have been extended to fixed-nuclei electron scattering [49, 178], an effective and computationally practicable treatment of rovibrational (rotational and vibrational) excitation requires a significant and historically challenging extension of bound-state theory.