ORBITAL DECIMATION IN MOLECULAR-SYSTEMS WITH AN AM1 HAMILTONIAN

Green's function method, with a renormalization strategy that allows f or stepwise hierarchical decimation of orbitals, is a powerful techniq ue for calculations in very large molecular systems. An interesting as pect of the decimation method is its relationship with the concepts of supramolecular chemistry. For donor-acceptor bridged systems, for exa mple, decimation may be done to find a two level representation, with an effective through-bond interaction, that is considered to control l ong distance electron-transfer in biological and other supramolecular systems. In the present work the decimation was applied for molecular systems with an AM1 Hamiltonian, that allows for geometry optimization and self-consistence.