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The structure of light nuclei in the p- and sd-shell features exotic phenomena like halos and clustering. In the Fermionic Molecular Dynamics (FMD) approach we aim at a consistent microscopic description of well bound nuclei and of loosely bound exotic systems. This is possible due to the flexibility of the single-particle basis states using Gaussian wave-packets localized in phase space. Many-body basis states are Slater determinants projected on parity, angular and total linear momentum. The structure of 12C is discussed. Here the ground state band can be well described within a shell model picture but excited states above the three-α threshold, including the famous Hoyle state, show a pronounced cluster structure. As another example we study the structure of the Neon isotopes 17–22Ne. In 17Ne we find a large s2 occupation related to a large charge radius. The charge radius decreases for 18Ne but gets again very large for 19Ne and 20Ne which is explained by significant admixtures of 3He and 4He cluster components into to the ground state wave functions. [ABSTRACT FROM AUTHOR]

Light nuclei in the p-shell are studied in the Fermionic Molecular Dynamics model. No a priori assumptions are made with respect to cluster structure or single-particle energies. The same effective interaction based on the Argonne V18 interaction is used for all nuclei. Short-range central and tensor correlations are treated explicitly using a unitary correlation operator. Calculations of binding energies and radii for Helium and Carbon isotopes are presented. The evolution of cluster and single-particle structures with increasing neutron number are discussed. The spectrum of 12C is calculated in a multiconfiguration calculation. The molecular structure of the excited states is investigated. © 2005 American Institute of Physics [ABSTRACT FROM AUTHOR]