Spin-adapted reduced Hamiltonians. II. Total energy and reduced density matrices

In the preceding paper (paper I of this series) the spin-adapted reduced Hamiltonian theory was developed and applied to the study of the elementary excitations of a test example; the Be atom. Here this theory is extended in order to obtain other observables: the total energy and the reduced density matrices for an m-electron system, always working within the two-body space. Preliminary applications of this formalism produce very satisfactory results.