| Popis: |
Correlation diagrams using orbital symmetry analogous to those of Woodward and Hoffmann for classifying concerted chemical reactions can be drawn for exact wavefunctions. The occupation numbers of the natural orbitals will normally show crossing between orbitals of high and of low occupation number for typical “forbidden” reactions and no such crossing for “allowed” reactions. Although not now adding any new predictive power, this picture provides the rules with a basis in terms of wavefunctions with exchange, correlation energy, and orbitals depending on occupancy, instead of the approximations of simple MO theory. |
