LOW-ENERGY-ELECTRON SCATTERING FROM THE WATER MOLECULE - ANGULAR-DISTRIBUTIONS AND ROTATIONAL-EXCITATION

The scattering of electrons from the H2O molecule in its ground electr onic state is analyzed by carrying out quantum calculations of the cou pled equations in the body-fixed (BF) frame and using exact static-exc hange 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 th e nonconvergent behavior of the angular distributions from fixed nucle i calculations involving polar molecules are carried out. Elastic and rotationally inelastic differential and momentum transfer cross sectio ns are compared with experiments and the effects on the inelastic proc esses 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. (C) 1998 American In stitute of Physics. [S0021-9606(98)00610-2].