We report elastic differential, integral, and momentum transfer cross-secti
ons for H2X molecules (X: O, S, Se, and Te) obtained at the static exchange
level of approximation. The energy range considered was from 2 up to 30 eV
for H2O and from 5 up to 30 eV for the other molecules. Our calculations w
ere performed with the Schwinger multichannel method with pseudopotentials
[M. H. F. Bettega, L. G. Ferreira, and M. A. P. Lima, Phys. Rev. A 47, 1111
(1993)], combined with a Born closure procedure in order to account for th
e long-range potential due to the permanent dipole moment of the targets. O
ur calculated cross-sections for H2O and H2S are in good agreement with oth
er theoretical results. Agreement with available experimental data is also
encouraging. It was found that molecular size plays a crucial role in the s
cattering process. The influence of heavy and H atoms in the collisions is
also discussed. For the integral cross-sections of the heavier molecules we
also investigated incident energies below 5 eV, looking for possible shape
resonances. Through the symmetry decomposition of the integral cross-secti
ons and the eigenphase sum analysis, we found shape resonances for H2S, H2S
e, and H2Te at the B-2 symmetry. For H2Te, we have also found a shape reson
ance at the A(2) symmetry. For all molecules a very broad structure was fou
nd at the A(1) symmetry. This is the first work to report such resonances f
or H2Se and H2Te. (C) 1999 American Institute of Physics. [S0021- 9606(99)0
1438-5].