We present results of the application of the Schwinger multichannel method
using effective configurations [Azevedo et al.. Phys. Rev. A 61, 042701 (20
00)] to study special features of low-energy electron-molecule scattering,
such as (i) the shape resonance in e(-)-N-2 scattering: (ii) the Ramsauer-T
ownsend minimum in e(-)-CH4 scattering: and (iii) a Feshbach resonance in e
(-)-H-2 scattering (in a two-channel coupling calculation including polariz
ation effects). In all cases, we find that the use of effective configurati
ons to describe polarization effects allows a substantial reduction of the
configuration spacer without any loss of quality of the results. The presen
t applications (together with our previous study of nonresonant electron-H-
2 scattering) indicate that this technique will be very useful in the analy
sis of more complex systems.