Scattering of low-energy electrons from polyatomic targets: the water molecule example

An ab initio, parameter-free model interaction is computed for the H₂O molecule as a target in low-energy electron scattering processes. The static, exchange and polarization correlation forces are evaluated according to computational procedures developed earlier by the author and collaborators specifically for polyatomic targets. The single-centre description of the target wavefunction was obtained via a fairly extended expansion on a basis set of Slater orbitals and the coupled equations of the body-fixed collision dynamics were solved at several energies, from approximately=1 eV up to 20 eV. Angular distributions for total cross sections, rotationally elastic and inelastic cross sections are compared with the available data and found to be in good agreement with them. The behaviour of the various eigenphase sums is also examined and the possible existence of broad shape resonances is discussed.