Reaction pathways that lead to products of the reactions in the [CHCl](2+) + D-2 system (CHCl+, CCl+, CHDCl+, HD2+, D-2(+), as observed experimentally) were studied using the CCSD(T)/cc-pVTZ method. Energies of located stationary points on the potential energy hypersurface were refined by the G2 method. Both isomers of the reactant dication CHCl2+-HCCl2+ (with H atoms bonded to C atoms) and CClH2+ (with H atoms bonded to Cl atoms)-were taken into consideration. The calculated reaction pathways were of importance in the interpretation of experimental beam-scattering data. The heats of formation of the reactant dications HCCl2+ and CClH2+ and of all relevant products ions (CCl+, HCCl+, CClH+, H2CCl+, HCClH+) were calculated.