Potential energy profiles characterizing the C-X bond cleavage in monolialomethanes CH3X (X = Cl, Br, I), polychlorinated methanes CHnCl4-n = (n = 0-3) and their anion radicals in water solutions were calculated using the density functional theory (DFT). In these calculations, solvent effects were accounted within the self-consistent reaction field (SCRF) model. The DIFT potential energy curves were fitted by a Morse and an exponential function for the initial molecules and their breakdown products, respectively. The model functions were then employed to describe the kinetics of reductive cleavage of the C-X bonds in the halomethanes. The relevant calculations were carried out based on the non-adiabatic quantum-mechanical theory of dissociative electron transfer (DET). The values of the calculated rate constants correlate well with published experimental data and also with theoretical results previously obtained by the semi-empirical PM3 method. (C) 2004 Elsevier B.V. All rights reserved.