It has previously been shown that partial widths of resonance states can be calculated by the asymptotic analysis of the complex scaled resonance wave function [U. Peskin, N. Moiseyev, and R. Lefebvre, J. Chem. Phys. 92, 2902 (1990)] and by the complex coordinate scattering theory [N. Moiseyev and U. Peskin, Phys. Rev. A 42, 255 (1990)]. Here we use these methods for the first time to calculate complex partial width amplitudes. The complex amplitudes are independent of the complex scaling parameters and are used for calculating the resonance contribution to the scattering matrix (the S matrix) in the case of Cl + H-2 scattering described by two coupled one-dimensional potential energy curves. The background contribution to the S matrix was calculated by the use of one ClH2 potential energy curve only. The sum of the resonance and the background contributions provides accurate complex S matrix elements and transition probabilities, even at the resonance energy for which total reflection is obtained due to the interference between the two contributions.