Insights into the electronic structure of molecules from Generalized Valence Bond theory - Thomas Harold Dunning

Generalized Valence Bond (GVB) theory provides a compelling description of the electronic structure of molecules. The GVB wave function is more accurate than the Hartree-Fock (molecular orbital) wave function, including the major non-dynamical correlation effects present in the valence complete active space self-consistent field (CASSCF) wave function. Unlike other multiconfiguration wave functions, the GVB wave function through the changes in the orbitals, spin couplings and overlaps provides unparalleled insights into the bonding, structure, and energetics of molecules. We will discuss a number of examples that illustrate the power of the GVB approach, including bonding in hypervalent molecules (SF4/SF6), vertex versus edge inversion in the PHnF(3-n) series, and the potential energy surface for the reaction of F2 with dimethylsulfide.