Studies of Light Neutron-Excess Nuclei from Bounds to Continuum.

The generalized two-center cluster model (GTCM), which can handle various single particle configurations in general two center systems, is applied to the light neutron-rich system, Be = α + α +4 N. We discuss the change of the neutrons' configuration around two α as a variation of an excitation energy. The covalent, ionic and atomic configurations coexists with the degenerate feature above the α + He particle-decay threshold. We find the strong enhancement in the monopole excitation from the ground state to the excited states. The GTCM calculation is also applied to even Be isotopes, and the systematics on the structural changes from bound region to continuum is discussed. [ABSTRACT FROM AUTHOR]