title: Electron transfer in proteins: nonorthogonal projections onto donor-acceptor subspace of the Hilbert space.
abstract: We develop nonorthogonal projectors, called Löwdin projectors, to construct an effective donor-acceptor system composed of localized donor (D) and acceptor (A) states of a long-distance electron transfer problem. When these states have a nonvanishing overlap with the bridge states these projectors are non-Hermitian and there are various possible effective two-level systems that can be built. We show how these can be constructed directly from the Schrödinger or Dyson equation projected onto the D-A subspace of the Hilbert space and explore these equations to determine the connection between Hamiltonian and Green function partitioning. We illustrate the use of these effective two-level systems in estimating the electron transfer rate in the context of a simple electron transfer model.
authors.affiliation: Departamento de Física, Universidade Federal do Paraná, 81531-990, Curitiba-PR, Brazil. pcandrade@fisica.ufpr.br
authors.forename: Paulo C P
authors.initials: PC
authors.lastname: de Andrade
authors.forename: José A
authors.initials: JA
authors.lastname: Freire
mesh_terms: D000465:Algorithms; D003198:Computer Simulation; D004579:Electron Transport; D008956:Models, Chemical; D008958:Models, Molecular; D011506:Proteins / Q000737:chemistry*
chemical_list: D011506:Proteins