ABSTRACT
The description of the steady states of atoms and molecules which may serve as reactants in chemical reactions is much more complicated than the description of a single particle. The solution of the Schrödinger equation for molecules is even more complicated since apart from the state of many electrons it is necessary to describe the state of the nuclei interacting with each other and with the electrons. A factor which somewhat facilitates the solution of this problem is the great difference in velocities of the electrons and nuclei. Consideration of kinetic processes in quantum mechanics associated with transitions between different steady states of a system is faced with the problem of solution of the time-dependent Schrodinger Equation. Totally quantum-mechanical treatments of the transition are necessary in order to find the criteria of applicability of the semiclassical method and to obtain the results in the cases where this method is inapplicable.
