Figure 5.

(a) Frontier orbitals of the molecule. The orbitals are either symmetric (GPH and GPL) or antisymmetric (GPH–1 and GPL+1) with respect to the center of the molecule. The frontier orbitals are shown in the gas phase for clarity (with the sulfur atoms “terminated” with one gold atom each) because they do not change significantly when the gold leads are attached to the molecule. (b) Conductance (horizontal black line in panel c) and total energy. (c) Transmission map of the molecule between two leads from DFT calculations. The horizontal yellow traces in the map arise from orbitals that can be related to the gas-phase frontier orbitals. An anti-resonance is observed between the frontier orbital traces. It shifts in energy as the displacement is varied. The positions at which the pairs of GPH–1 and GPH and of GPL and GPL+1 degenerate are marked with circles.