2. Given the initial set s, initialize w using the magnitude of the eigenvector components for the k × k Hamiltonian submatrix spanned by the determinants in s. For values of w i / ∈ s, the initial value is estimated using the perturbation theory expression in Eq. (22). In general, the values of w i ∈ s and w i / ∈ s, which combine to form the initial vector w, are not on the same scale as they are estimated from different procedures.