A symmetry-adapted SCF method

As we shall see in a later chapter, if we make the further constraint on the SCF method that the molecular orbitals are symmetry-adapted, then the above technique can be extended in such a way that only the symmetry-distinct integrals need be computed and stored What is more, the restriction to permutational symmetries can be removed so that the full molecular point group symmetry can be used, which may involve operations which induce linear combinations among the basis functions. 

In the most popular version of the SCF Cl method, in a first stage the basis functions are optimized from a single-configuration Hartree-Fock calculation and then used for the construction of the various configurations (combinations of Slater determinants adapted to the spin symmetry) which make up the correlated wave function... 

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