Effects of long-range dispersive interaction on the electron transport in short single strands of guanine bases

We study the effects of the long-range dispersive interaction on the electron transport in short single strands of guanine bases (G)s employing the density functional theory combined with non-equilibrium Green's function method. Effects of contacting position are considered by connecting atomic gold chain electrodes on different positions to adapt to possible realistic measurements. The dispersive interaction can modify the stacking structure and enhance the helicity of the molecules. The corresponding change in the electronic structure may result in much-increased conductance and the rectification effect. The dispersive interaction may also be the key to the realization of first-principles simulation of some systems.