Exponential parametrization of the configuration space

The parametrization of the state-averaged MCSCF energy (12.7.4) adopted in the present subsection differs hum the single-state parametrization introduced in Section 12.2.1 Since we require the states to be orthogonal (12.7.2), it is no longer convenient to employ, as our primary variational parameters, the individual Cl coefficients of the expansions (12.7.1). Instead, we base our description on the exponential parametrization of the configuration space of Section 12.6 and write the MCSCF wave functions in the form... 

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