Ab initio polarisation potential in the random-phase approximation: application to e--H2elastic scattering

The interaction potential of e - -molecule scattering is formulated in terms of the optical potential of many-body theory. In particular, dynamic polarisation effects directly follow from an RPA solution to the target linear response function. It is further pointed out that such a level of accuracy can most easily be obtained by simply working within the formalism of Hartree-Fock theory. An adiabatic approximation to the full optical potential is finally derived and explicitly applied to the e - -H 2 system, showing good agreement with alternative ab initio formulations of the literature.