The Landauer transmission was calculated using the nonequilibrium Green's functions (NEGF) approach as implemented in our inhouse wide-band transmission code, which is described in detail in previous work. Transmission plots for all molecules we studied are shown in Figure . Computations of both the zero-bias transmission and the low-bias current density were carried out using DFT at the PBE/dzp level as implemented in ASE and GPAW. The current density was computed with a symmetric bias of 100 mV, which is opened around the Fermi energy unless otherwise noted. Conservation tests of the current density are carried out and included in Supporting Information. The wide-band transmission and current density code is openaccess and available at .