A generalized multistructural wave function

A generalized multistructural (GMS) wave function is presented which combines the advantages of the self-consistent-field molecular orbital (SCF-MO) and valence bond (VB) models, preserving the classical chemical structures but optimizing the orbitals in a self-consistent way. This wave function is particularly suitable to treat situations where the description of the molecular state requires localized wave functions. It also provides a very convenient way of treating the electron correlation problem, avoiding large configuration interaction (CI) expansions. The final wave functions are much more compact and easier to interpret than the ones obtained by the conventional methods, using orthogonal orbitals. Applications of the GMS wave functions to a variety of systems are presented.