A SEQUENTIAL FORMULA FOR ELECTRONIC COUPLING IN LONG-RANGE BRIDGE-ASSISTED ELECTRON-TRANSFER - FORMULATION OF THEORY AND APPLICATION TO ALKANETHIOL MONOLAYERS
Cp. Hsu et Ra. Marcus, A SEQUENTIAL FORMULA FOR ELECTRONIC COUPLING IN LONG-RANGE BRIDGE-ASSISTED ELECTRON-TRANSFER - FORMULATION OF THEORY AND APPLICATION TO ALKANETHIOL MONOLAYERS, The Journal of chemical physics, 106(2), 1997, pp. 584-598
A recursion relation is formulated for the Green's function for calcul
ating the effective electron coupling in bridge-assisted electronic tr
ansfer systems, within the framework of the tight-binding Hamiltonian.
The recursion expression relates the Green's function of a chain brid
ge to that of the bridge that is one unit less. It is applicable regar
dless of the number of orbitals per unit. This method is applied to th
e system of a ferrocenylcarboxy-terminated alkanethiol on the Au(111)
surface. At larger numbers of bridge units, the effective coupling str
ength shows an exponential decay as the number of methylene(-CH2-) uni
ts increases. This sequential formalism shows numerical stability even
for a very lung chain bridge and, since it uses only small matrices,
requires much less computer time for the calculation. Identical bridge
units are not a requirement, and so the method can be applied to more
complicated systems. (C) 1997 American Institute of Physics.