Permutational symmetry energy functional form

The symmetric combination corresponds to a + state, and since it must be combined with the antisymmetric spin function, we have a 1 + state, the highest energy state arising from the ground electron configuration. The antisymmetric combination in (6.75) is a state, and combined with the symmetric triplet spin functions forms the ground state, 3 g. We discuss permutation and inversion symmetry in much more detail later in this chapter. 

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