Abstract:
The nonlocal resonance model developed previously
for the description of low-energy electron collisions with hydrogen halides
is generalized to include the
dependence of the dipole-modified threshold exponent
on the internuclear distance. An efficient computational scheme has been
developed to deal with the resulting
nonseparability of the nonlocal complex potential
for the nuclear motion within the Schwinger-Lanczos approach. The results
reveal that the R-dependence of the
threshold exponent has a significant effect on
the threshold peaks in the vibrational excitation cross sections of HCl.
The shape and intensity of the calculated
threshold peak in the 0 --> 1 vibrational excitation
channel, in particular, are in much better agreement with experimental
data than previous results. For the
electron-HBr and electron-HI collision systems
the effects of the R-dependence of the threshold exponent are not significant.