The photodetachment spectrum of ClH2-, probing the van der Waals well region of the coupled multi-sheeted reactive Cl+H-2 potential energy surfaces, is theoretically calculated with the aid of a time-dependent wave packet approach. The theoretical findings are compared with the available experimental results [J. Chem. Phys. 117 (2002) 8181]. The calculated photodetachment spectrum reveals resolved structures that can be attributed to the low-frequency van der Waals progression. The spectral envelopes are similar to0.1 eV apart in energy (nearly equal to the spin-orbit splitting of similar to0.109 eV of atomic Cl) in accord with the experiment. The congestion of the spectral lines in the coupled states results mainly arises from the non-adiabatic effects due to spin-orbit coupling. (C) 2004 Elsevier B.V. All rights reserved.