Ab initio nonadiabatic polarization potentials for electron-molecule scattering: The e-H2 system

We have calculated an ab initio nonadiabatic polarization potential for the e-H2 system using a procedure that is based on the variational method. The importance of various multipole contributions to this potential has been investigated and the dipole approximation found to be accurate for this system. When used in scattering calculations with accurate representations of the static and exchange components of the interaction potential, the new polarization potential is found to yield total integrated e-H2 cross sections that are in very good agreement with results of recent measurements and of optical-potential calculations.