We study the electrical characteristics of a group of glycine oligopeptides (1-, 3-, 6-, and 9-mers) molecules attached to gold nanoelectrodes using a combined density functional theoryGreen's function approach. Our procedure considers the applied voltage through the molecule and contacts, recalculates self-consistently the molecular orbitals, Hamiltonian and overlap matrices at each applied voltage, and uses these results to estimate the current−voltage characteristics such that the chemistry of the molecule is fully considered when including the effect of the nanoelectrodes.
