Abstract
By employing semi-empirical spherical complex optical potentials (SCOP) for the electron-H2O and NH3 systems, the author reports first theoretical results on the total (elastic+inelastic) cross sections over the energy range of 10-3000 eV. The real part of the local SCOP term for each molecule is a sum of three isotropic interactions, namely the static, the polarisation and the exchange; all three potentials are defined in a functional form of the target charge density evaluated from near-Hartree-Fock one-centre molecular wavefunctions. The contribution from the non-spherical interaction terms (such as the permanent dipole, quadrupole, etc.) is included incoherently via the first Born approximation under the rotating molecule model in which the integral cross section is finite.