Earlier work [Chem. Phys. Lett. 206 (1993) 123] has derived an especially convenient expression for the S-matrix of an inelastic or reactive scattering process in terms of an L 2 representation of the Green function with a finite absorbing potential. Here we discuss some special features that arise when one applies this expression to the special case of elastic scattering. This is particularly relevant in scattering applications where one is primarily interested in reflected (i.e., elastically scattered) waves.