Figure 8.

KIE versus r_tun for the Kuznetsov and Ulstrup vibronic model (19,23) compared to the AADH KIE calculated using Eqs. 1–5 and plotted versus r_tun for H (as opposed to D) transfer. The X-H bond in the vibronic model is described using both a quantum harmonic oscillator (a) and a quantum Morse oscillator (b) as described by Meyer and Klinman (51). Vibronic model was calculated both without a promoting vibration (solid lines) and with a fairly stiff promoting vibration (dashed lines), with the same force constant used in our previous study (160 J m⁻² (19)). Parameters for describing the proton wavefunction are given in Fig. S9.