A many-body calculation of ${}_{}{}^{11}{}_{}{}^{}\mathrm{Li}$ is presented where the only input is the well-tested, finite-range D1S effective interaction of Gogny. The nucleus ground state is modeled as a GCM configuration mixing of Hartree-Fock-Bogolyubov states generated with a constraint on the mean square radius. Pairing correlations are computed from the two-body interaction itself. The kinds of correlations included in this way are found to play an important role in describing the large ${}_{}{}^{11}{}_{}{}^{}\mathrm{Li}$ radius. A substantive underlying ${}_{}{}^9{}_{}{}^{}\mathrm{Li}$ core of ${}_{}{}^{11}{}_{}{}^{}\mathrm{Li}$ is found, which has a different density profile than a free ${}_{}{}^9{}_{}{}^{}\mathrm{Li}$ nucleus. The relations of this work with other approaches are discussed.

• Received 3 August 1994

DOI:https://doi.org/10.1103/PhysRevC.52.669