| Abstract: | The theory of an implementation of the diabatic surface model within the Heitler–London valence bond approach is described. It is shown that the HL –VB wave function can be obtained from a Van-Vleck transformation of an MC –SCF wave function which has been built from atom-localized orbitals. This wave function is built from a superposition of two diabatic components, reactantlike and productlike. The transition structure is then obtained as the minimum of the seam of intersection of the diabatic surfaces and the algorithm for performing this constrained optimization is described. Several areas of application are also discussed. |
