  Consider the Schroedinger operator with semiclassical parameter h, in the
limit where h goes to zero. When the involved long-range potential is smooth,
it is well known that the boundary values of the operator's resolvent at a
positive energy E are bounded by O(1/h) if and only if the associated Hamilton
flow is non-trapping at energy E. In the present paper, we extend this result
to the case where the potential may possess Coulomb singularities. Since the
Hamilton flow then is not complete in general, our analysis requires the use of
an appropriate regularization.
