Vibrationally assisted tunneling

To feature the vibration-assisted tunneling, a convenient object for simulations, is the hydrogenoxalate anion... 

G. V. Mil nikov, O. Kuhn, and H. Nakamura, Ground state and vibrationally assisted tunneling in the formic acid dimer. J. Chem. Phys. 123, 074308 (2005). 

This is quite different from the first two. Due to the reflection symmetry of this potential, the instanton path always remains directed along the Q axis. The transverse q vibration changes only the width of the reactive channel according to Eqs. (4.23) and (4.24). When C > 0, the vibrational-ly adiabatic squeezed barrier is greater than the bare one. This case of dynamically induced formation of the barrier was studied by Auerbach and Kivelson [1985] in context of nuclear physics. The opposite case C < 0, corresponding to the vibration-assisted tunneling, will be considered in Section 8.3. 

These studies provide direct experimental confirmation of the vibration-assisted tunneling model. The fluorescence excitation spectrum... 

This model is based on the weak coupling approximation and it takes into account neither reorganization nor vibration assistance in the sense of Section 2.5. Although the term vibration-assisted tunneling is also applied to the Skinner-Trommsdorf model, this assistance signifies only that vibrations supply the energy needed to provide a resonance. 

Basran, J., Patel, S., Sutcliffe, M. J., Scrutton, N. S. (2001) Importance of barrier shape in enzyme-catalyzed reactions - vibrationally assisted tunneling in tryptophan tryptophyl-... 

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