UNRESTRICTED SYMMETRY-PROJECTED HARTREE-FOCK-BOGOLIUBOV CALCULATIONS FOR SD-SHELL NUCLEI

The solution of the Hartree-Fock-Bogoliubov problem with restoration o f the broken symmetries before the variation has been generalized for the use of totally unrestricted quasi-particle determinants. With this method doubly-even, doubly-odd and odd nuclei can be treated on the s ame footing. Comparison with the results of complete shell-model diago nalizations shows that already one-determinant representations yield a very good approximation to the exact solutions even in the middle of the 1s0d shell. The problem is especially suited for numerical impleme ntation on parallel computers. First tests show a linear dependence of the inverse CPU time with the number of processors used.