Variational transition state theory with multidimensional tunnelling and kinetic isotope effects in the reactions of C 2 H 6 , C 2 H 5 D and C 2 D 6 with .CCl 3 to produce CHCl 3 and CDCl 3

CCl 3 . for the production of CHCl 3 and CDCl 3 ( k 1 , k 2 , k 3 and k 4 ) were computed using variational transition state theory coupled with hybrid-meta density functional theory (MPWB1K) over the temperature range of 200–2900 K. The ground-state vibrational adiabatic potential was plotted for all channels. Small- and large-curvature tunnelling were determined to include quantum effects in the calculation of rate constants.

Harmonic vibrational frequencies along the reaction path were calculated in curvilinear coordinates with scaled frequencies. Anharmonicity was included in the lowest-frequency torsion. The position of formation and dissociation of bonds was specified using the variation in harmonic vibrational frequencies along the reaction path.