We used the Schwinger multichannel method with pseudopotentials [Bettega et
nl., Phys. Rev. A 47, 1111 (1993)] to study elastic scattering of low-ener
gy electrons by the boron trihalides BCl3, BBr3, and BI3, at the static-exc
hange approximation. We calculated elastic integral, differential, and mome
ntum transfer cross section from 5 to 50 eV. In particular, our integral cr
oss section fur BCl3 agrees in shape with results of previous calculations
by Isaacs et al. [Phys. Rev. A 58, 2881 (1998)]. The symmetry decomposition
of the integral cross section in the C-2v group is also presented. We disc
uss the existence of shape resonances for energies above 5 eV at the A(1),
B-1, B-2, and A(2) symmetries. We also investigated the low-energy cross se
ction for the B-2 symmetry for these three molecules. For BCl3 our B-2 cros
s section shows good agreement with the results of Isaacs et al.