Hagedorn G.A. , Joye A.
Landau-Zener Transitions Through Small Electronic
Eigenvalue Gaps in the Born-Oppenheimer Approximation
(118K, Latex)
ABSTRACT. We study the propagation of molecular wave packets through the simplest two
types of avoided crossings of electronic energy levels in a limit where the gap
between the eigenvalues shrinks as the nuclear masses are increased. For these
types of avoided crossings, the electron energy levels essentially depend on only
one of the nuclear configuration parameters, as is the case for all diatomic molecules.
We find that the transition probabilities are of order 1 and are determined by the
Landau-Zener formula.