Energy extended generating functionals

See for example Oxtoby, D. W. Nucleation of first-order phase transitions, Acc. Chem. Res. 1998, 31, 91-97, and references therein. The classical nucleation theory (CNT) is challenged by extended theories, one of which was unfortunately called density functional theory because free energy is a functional of the average density profile of the nucleating site, generating some confusion, at least for theoretical chemists, with quantum chemical density functional theory. 

The dissociation problem is solved in the case of a full Cl wave function. As seen from eq. (4.19), the ionic term can be made to disappear by setting ai = —no- The full Cl wave function generates the lowest possible energy (within the limitations of the chosen basis set) at all distances, with the optimum weights of the HF and doubly excited determinants determined by the variational principle. In the general case of a polyatomic molecule and a large basis set, correct dissociation of all bonds can be achieved if the Cl wave function contains all determinants generated by a full Cl in the valence orbital space. The latter corresponds to a full Cl if a minimum basis is employed, but is much smaller than a full Cl if an extended basis is used. 

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