Dipole molecular configurations in unbound (16O + 12C), and bound (18O and sup(218,220)Ra) nuclear systems

Studies of nuclear molecular configurations in bound and unbound systems are reported. Rotational bands of alternating parity states with large reduced cluster widths are found as resonant states in 16O + 12C and as bound states in 18O and sup(218,220)Ra. In the bound systems, enhanced El deexcitations are found, as suggested by the Vibron cluster model of Iachello-Jackson. An absolute scale for the El enhancement is given by a dipole molecular sum rule. A discussion of the model and the underlying, newly suggested, dipole collectivity is presented. (author)