Adiabatic crossing

Tully, J. C. Nonadiabatic Processes in Molecular Collisions. In Dynamics of Molecular Collisions, Part B (W.H. Miller, ed.). Plenum, New York (1976) Zener, C. Non-adiabatic crossing of energy levels, Proc. R. Soc. London, Ser. A 137 (1932) 696-702... 

Zener C (1932) Non-adiabatic crossing of energy levels. Proc Roy Soc A137 696... 

Morrison, M.A., Abdolsalami, M. and Elza, B.K. (1991). Improved accuracy in adiabatic cross sections for low-energy rotational and vibrational excitation, Phys. Rev. A 43, 3440-3459. 

Figure 9.25. Time-dependent population of the target diabatic (a) or adiabatic (b) state obtained from exact solution of the Zener problem for two values of the Massey parameter = 0.01 [(a) nonadiabatic crossing] and = 2.25 [(fo) adiabatic crossing]. Time is in units of Tna =...

Figure 4. Portion of subsonic adiabats for n-octane with upstream states on selected spinodal points and subsonic downstream states. Initial states are labeled by the reduced temperature = T/Tc. Downstream states are mixtures for initial points of Tr = 0.95 and 0.93 the adiabat crosses the saturation curve for % = 0.917 the adiabat lies completely in the vapor region for = 0.9108.

Lobo and Ramanathan have combined adiabatic and Hartmann-Hahn cross-polarization for sensitivity enhancement in solid-state separated local field 2D NMR experiments of partially ordered systems The magnetization in double- and zero-quantum reservoirs of an ensemble of spin-1/2 nuclei has been examined and their role in determining the sensitivity of a class of separated local field NMR experiments based on Hartmann-Hahn cross-polarization has been described. Lobo and Ramanathan report that for the liquid crystal system studied, a large dilute spin-polarization, obtained initially by the use of adiabatic cross-polarization, can enhance the sensitivity of the above experiment. The signal enhancement factors, however, are found to vary and depend on the local dynamics. The experimental results have been utilized to obtain the local order-parameters of the system. 

Fig. 3 NMR spectra of 5CB at 298 K showing the signal enhancement from the use of adiabatic cross-polarization (b), in comparison to the single-pulse experiment (a). (Reproduced with permission from J. Chem. Phys., 2008, 128, 114504.)...

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