Electronic transmission of benzene metallic junctions: Reliability range of perturbation values

In this paper, the electronic transmission of an electrode-benzene-electrode system using equilibrium green's and first order perturbation theory is investigated. the effect of different values of perturbation on substitution of the electrode into the different atomic sites is presented. the range of the perturbation values are from zero to the energy gap between the highest occupied and the lowest unoccupied molecular orbitals. our calculations indicate that increasing the perturbation value does not greatly affect the case where the connection is with maximum transmission (para), whereas, doing likewise for the case of minimum transmission (ortho), we find a much more sensitive transmission response.