Theoretical study of molecular conduction: I. Effective Green's function based on perturbation theory



There have been many experimental and theoretical studies on molecular conduction, as it is a fundamental parameter in the study of molecular-scale electronics. We have investigated the features of molecular conduction using a Green's function method, which has often been used to solve problems in quantum transport and is also effective in elucidating electron transport in molecules. We have obtained the novel effective Green's functions, including the first-order energy corrections, by accommodating the self-energy of the electrodes as perturbation terms. Although these approximate Green's functions only provide information on the first-order energy corrections, they can involve the elementary properties of molecular conduction. We propose a scheme for the analysis of the relations between molecular orbitals and their roles in molecular conduction and present analytical calculations for normal and cyclic polyenes. © 2005 Wiley Periodicals, Inc. Int J Quantum Chem, 2006