Reliability of gaussian based ab initio methods in the calculations of HClO and HOCl decomposition channels

The singlet potential energy surface of the O(1D)+HCl→OH+Cl, and the O(1D)+HCl→H+ClO reactions, (X=Cl, Br) were computed with the G2, CBS-Q, and CBS-QB3 methods, and we were able to obtain very reliable information about the relative energies can be obtained (i.e. barrier heights, dissociation energies, etc.). We have examined the above-mentioned reactions, the HOCl→HClO isomerization, and multiple dissociation pathways for both HOCl and HClO. The CBS-QB3 methods seems to produce the most reliable results.