We apply CIP and constrained DFT (cDFT) to overcome these restrictions and model biased interfaces with real-space methods without localized basis functions or Wannierlocalized orbitals, see Section 4 and Supporting information Section S4 for more computational details. Figure between the electrodes and a bias across the molecular junction. By comparing the equilibrium and non-equilibrium electrostatic potentials (Figure ) obtained from DFT and cDFT calculations, respectively, we observe that the application of cDFT results in a 1 V bias (∆ϕ DF T -cDF T ) across the 1,4-dithiol-phenylene junction. This finding is in very good agreement with the more elaborate MS-DFT method (see Figure of Ref. ). The detailed analysis of CIP-DFT and MS-DFT in the Supporting information Section S4, we conclude that CIP-cDFT accurately describes the bias across an electrochemical cell with similar accuracy to the more involved Green's function or MS-DFT methods. The CIP-cDFT approach therefore provides a solution to the long-standing issue of simulating a finite bias in a two-electrode cell with DFT.