Scattering cross sections for collisions of electron with water molecules in the energy range 0.1–100 eV

Scattering cross sections for the electron impact on H 2 O molecules have been reported using a parameter-free spherical complex optical potential (SCOP) approach in the fixed-nuclei approximation at energies from 0.1 to 100 eV. The optical potential which is a sum of a real and an imaginary potential is constructed from a near-Hartree-Fock one-center-expansion of projectile-target interaction. In the present work, the calculations are performed within a spherically averaged (isotropic) potential framework and does not explicitly include the dipole moment of the H 2 O molecule; therefore, the reported results correspond to electron scattering from spherical component of the interaction potential and, below the electronic excitation threshold, should be interpreted as purely electronic elastic cross sections without rotational excitation contributions. The present calculated cross sections are compared with the available calculations and experimental measurements in this energy region. The qualitative feature of the scattering parameters [such as shape resonance structure and a sort of Ramsauer Townsend (RT) minimum], as observed in some experiments are reproduced in the present calculation. The value of the RT minimum has been correlated with the scattering length to the dipole polarizability of the target molecule.