{ital Ab} {ital initio} based effective Hamiltonians for long-range electron transfer: Hartree{endash}Fock analysis

Journal Article · Sun Dec 01 04:00:00 EST 1996 · Journal of Chemical Physics

DOI:https://doi.org/10.1063/1.472788· OSTI ID:397442

Kurnikov, I V; Beratan, D N ^[1]

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1. Department of Chemistry, University of Pittsburgh, Pittsburgh, Pennsylvania 15260 (United States)

An {ital ab} {ital initio} electronic structure method is developed to describe electron transfer in large systems. The method is based on a molecular fragment effective Hamiltonian approach. The strategy pieces together results of {ital ab} {ital initio} quantum chemistry calculations on overlapping molecular segments in order to build an effective Hamiltonian that describes the long-range electronic interactions. This is accomplished by constructing fragment effective Hamiltonians that properly describe the electronic propagation characteristics of each fragment (computed at the {ital ab} {ital initio} Hartree{endash}Fock level in an appropriate basis set). The fragment effective Hamiltonian is projected onto the valence orbital space of each fragment, and a relatively well-localized set of effective interactions is obtained. Combining these projected fragment Hamiltonians allows the construction of a valence effective Hamiltonian for the entire system. We find that the fragment Hamiltonian matrices constructed in this way are transferable between donor{endash}acceptor systems with homologous electron-transfer bridges. The overall strategy of fragmentation and construction of valence effective Hamiltonians could enable {ital ab} {ital initio} quality computations of long-range tunneling interactions in macromolecules. We demonstrate the use of the method in a series of electron-transfer model systems of modest size. {copyright} {ital 1996 American Institute of Physics.}

• DOE Contract Number: FG36-94GO10051
• OSTI ID: 397442
• Journal Information: Journal of Chemical Physics, Journal Name: Journal of Chemical Physics Journal Issue: 21 Vol. 105; ISSN JCPSA6; ISSN 0021-9606
• Country of Publication: United States
• Language: English

Related Subjects

66 PHYSICS
AB INITIO CALCULATIONS
BIOLOGICAL MATERIALS
ELECTRON TRANSFER
ELECTRONIC STRUCTURE
HAMILTONIANS
HARTREE-FOCK METHOD
MACROMOLECULES
PROTEIN STRUCTURE
QUANTUM CHEMISTRY