Quadrupole Deformation β and γ Constraint in a Framework of Antisymmetrized Molecular Dynamics

We propose a new method of the beta-gamma constraint for quadrupole deformation in antisym-metrized molecular dynamics (AMD) to describe various cluster and shell-model structures in the ground and excited states of light nuclei. We apply this method to N = 6 isotones, Be-10, C-12, Li-9, and B-11, and find various structures as functions of the deformation parameters, beta and gamma. In these nuclei, shell-model-like structures appear in the small beta region, while cluster structures develop well in the large beta region where various geometric configurations of clusters are obtained depending on the gamma parameter. For Be-10 and C-12, we superpose the basis AMD wave functions obtained by the beta-gamma constraint method to calculate energy spectra, and prove the advantages of the present method of the two-dimensional beta-gamma constraint in the framework of AMD.