Saddle-point energy

Carlo-simulations for LI2 superlattice including saddle-point energies for atomic jumps in fact yielded two-process kinetics with the ratio of the two relaxation times being correlated with the difference between the activation barriers of the two sorts of atom. 

Figure 16. Projections onto 2D surfaces of trajectories (in green) of CH3O H2 + HCO. The left column is a projection onto the surface of Fig. 15. The right column is a projection onto the surface of Fig. 14. The black contour represents the saddle point energy for the H+ H2CO H2 + HCO reaction. Blue contours are lower in energy red contours are higher. Reprinted with permission from [67], Copyright 2001 American Chemical Society. (See color insert.)...

A is a measure for the energy required to reorganize the inner and outer sphere during the reaction. The energy of activation for the oxidation is the saddle point energy minus the initial energy ered, which gives ... 

We begin our discussion with the diffusion of a Si adatom over a flat terrace. This problem has previously been addressed with ab initio calculations for the case of symmetric dimers. The main result is that diffusion is highly anisotropic on the surface, with fast diffusion taking place over the top of the dimers with a saddle point energy of about 0.60 eV. Slow adatom diffusion is predicted to take place across the dimer rows with a barrier of 1.0 eV. Experiments based on a number counting of the island density are in agreement with these results. ... 

Furthermore, recent radiotracer experiments have shown that metals such as Cu, Ag, and Au can diffuse into various polymers including polyimides and polycarbonates at elevated temperatures. Arrhenius type temperature dependences are not always found. This is not unexpected considering the distribution of saddle-point energies in amorphous polymers [F. Faupel, R. Willecke (1994)]. 

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