Molecular collective vibrations in the ternary neutronless fission of Cf-252

Based on a recent experimental finding which may suggest the existence of a trinuclear molecular structure before the cold ternary fragmentation of Cf -252 takes place, we solved the eigenvalue problem of a certain class of vi brations which are very likely to occur in these molecules. These oscillati ons are the result of the joint action of rotations of the heavier fragment s and the transversal vibrations of the lighter spherical cluster with resp ect to the fission axis. In the calculation of the interaction between the heavier fragments we took into account higher multipole deformations, inclu ding the hexadecupole one, and introduced a repulsive nuclear part to ensur e the creation of a potential pocket in which a few molecular states can be accommodated. The possibility to observe the de-excitation of such states is discussed in connection with the molecular lifetime.