NUCLEONIC MOLECULAR-ORBITALS AND LANDAU-ZENER TRANSITIONS IN HEAVY-ION REACTIONS WITH THE DIABATIC BASIS

The validity of nucleon-molecular-orbital picture is discussed for the C-12 + C-13 system by using the orthogonalized coupled-reaction-chann el rotating molecular-orbital (RMO) model. Specific RMO states, namely positive-parity ground RMO states, are well described by the picture of a covalent molecule, while the adiabaticity for RMO states is not s atisfied in general because of the appearance of Landau-Zener radial c ouplings in the RMO basis. However, we show, by transforming the RMO b asis to a diabatic basis, that the adiabatic molecular-orbital picture is again established. Momentum-dependent coupling interactions domina te transition phenomena in this diabatic basis, contrary to the assump tion made in the classical Landau-Zener theory.