A translationally invariant shell-model treatment of (0+1) ħω states in a=4–16 nuclei (I)

Shell-model calculations on positive- and negative-parity states have been performed for thep-shell nuclei. The model space includes all 0?ω and 1?ω harmonic-oscillator basis states without the use of a core. The matrix elements of the mass-independent two-body interaction and the harmonic-oscillator size parameter are determined empirically from a fit to experimental energy levels. The interaction is required to satisfy translational invariance. The single-particle energies are compatible with this requirement. The spurious states are isolated exactly from the nonspurious states.