Instead, we follow the same path as the MELD and SCIEL codes, and identify all the spatial occupation pa erns associated with the determinants. We then generate all associated spin-ipped con gurations, and add to the internal space all the missing determinants. is procedure ensures that Ĥ commutes with Ŝ2 in the truncated space, and spinadapted states are obtained by the diagonalization of Ĥ. In addition, we apply a penalty method in the diagonalization by modifying the Hamiltonian as 118