The structure of stable and unstable light nuclei in the carbon region is investigated using the extended version of the Antisymmetrized Molecular Dynamics Multi-Slater Determinant model. This method has proved to be very flexible when describing structure of light nuclei where both shell model and cluster structure can appear. In this paper we address specifically the development of cluster structure in the 0(2)(+) state in the Be-10 isotope. The possibility of description of halo structure within the adopted method is discussed in the case of C-15. Systematic calculations for even-even oxygen isotopes support the development of new magic number N=16
