Multiconfigurational self-consistent field MCSCF model

The computational model capable of yielding accurate spin-spin coupling constants is the multiconfigurational self-consistent field (MCSCF) model, and before the advent of density functional theory, spin-spin coupling constants in small systems were often... 

We start out with a section on the energy functionals and Hamiltonians that are relevant for molecular systems interacting with a structured environment. We continue with a section that briefly describes the correlated electron structure method, the multiconfigurational self-consistent field (MCSCF) electronic structure method. In the following section we cover the procedure for obtaining the correlated MCSCF response equations for the two different models describing molecules in structured environments. The final sections provide a brief overview of the results obtained using the two methods and a conclusion. 

As the next standard model of quantum chemisUy, we consider here the generalization of the Hartree-Fock wave function to systems dominated by more than one electronic configuration the multiconfigurational self-consistent field (MCSCF) wave function. This flexible model may be useful for describing the electronic structure of bonded molecular systems, in particular for excited states. Perhaps more important, however, is its ability to describe bond breakings and molecular dissociation processes. 

In Chapter 12, we study the related multiconfigurational self-consistent field (MCSCF) method, in which a simultaneous optimization of orbitals and Cl coefficients is attempted. Although the MCSCF method is incapable of providing accurate energies and wave functions, it is a flexible model, well suited to the study of chemical reactions and excited states. This chapter concentrates on techniques of optimization, a difficult problem in MCSCF theory because of the simultaneous optimization of orbitals and Cl coefficients. 

MCSCF, the multiconfigurational self-consistent field model... 

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