Isotope effects, hydrogen bond relaxation

In contrast to the subsystem representation, the adiabatic basis depends on the environmental coordinates. As such, one obtains a physically intuitive description in terms of classical trajectories along Born-Oppenheimer surfaces. A variety of systems have been studied using QCL dynamics in this basis. These include the reaction rate and the kinetic isotope effect of proton transfer in a polar condensed phase solvent and a cluster [29-33], vibrational energy relaxation of a hydrogen bonded complex in a polar liquid [34], photodissociation of F2 [35], dynamical analysis of vibrational frequency shifts in a Xe fluid [36], and the spin-boson model [37,38], which is of particular importance as exact quantum results are available for comparison. 

Isotope effects have been used to provide information on the electronic transmission paths between the metal and the nuclei in first and second coordination spheres. Thus, the two-bond deuterium isotope effect A( H) on going from C5H5V(CO)4 to C5D5V(CO)4 (—0.75 ppm per has been discussed in terms of non-negligible overlap between hydrogen and metal orbitals [33]. The distinct two-bond coupling derived from relaxation... 

---