Fig. 4

DFT+NEGF calculations on the PDI8-CN₂ molecule. a Frontier orbitals of a PDI8-CN₂ molecule in gas phase calculated from DFT. HOMO, LUMO and LUMO+2 are called, respectively, as H, L, and L+2. b NEGF calculations of the transmission through N-to-N atoms of the cyano groups (red curve) and N-to-N atoms located at the side positions (blue curve). The dashed line indicates the mid-gap energy between H and L