GENERALIZED MODELS OF NONADIABATIC TRANSITIONS L. Pichl$^\ast$, V. I. Osherov$^\sharp$ and H. Nakamura$^\ast$ $^\ast$Institute of Molecular Science, Okazaki, Japan $^\sharp$Institute of Chemical Physics (Russian Academy of Sciences), Moscow, Russia Within the framework of the exponential model we developed an analytical formula for nonadiabatic transition matrix by means of semiclassical methods. The exponential model can cover both basic Landau-Zener-Stueckelberg (LZS) and Rozen-Zener-Demkov (RZD) type of transitions. We introduce general parameters for the transition matrix as contour integrals of adiabatic momenta in the coordinate plane. These (model-independent) quantities can be used for more general potentials.