Low-energy electron scattering from the water molecule: Angular distributions and rotational excitation

The scattering of electrons from the H2O molecule in its ground electronic state is analyzed by carrying out quantum calculations of the coupled equations in the body-fixed (BF) frame and using exact static-exchange interaction forces (ESE) within a single-center expansion (SCE) formulation. The effect of correlation-polarization forces is included via a density functional approach and the necessary corrections to the nonconvergent behavior of the angular distributions from fixed nuclei calculations involving polar molecules are carried out. Elastic and rotationally inelastic differential and momentum transfer cross sections are compared with experiments and the effects on the inelastic processes of the long-range dipolar potential are examined in some detail. The electron efficiency in exciting molecular rotations over a broad range of energies is also obtained and discussed.