We propose a simple scheme that describes accurately essential nonequilibrium effects in nanoscale electronics devices using equilibrium transport theory. The scheme, which is based on the alignment and dealignment of the junction molecular orbitals with the shifted Fermi levels of the electrodes, simplifies drastically the calculation of current-voltage characteristics compared to typical nonequilibrium algorithms. We probe that the scheme captures a number of nontrivial transport phenomena such as the negative differential resistance and rectification effects. It applies to those atomic-scale junctions whose relevant states for transport are spatially placed on the contact atoms or near the electrodes. Nanoscale devices tend to suffer from a serious lack of reproducibility from one research group to another, and from a lack of durability and robustness. 1,2 However, the consistent and thorough work of a range of experimental groups has allowed researchers to reach some consensus on the conductance values and variability of a few specific junctions. [3][4][5] In addition, the development of simulation codes based on a combination of density functional theory (DFT) and the nonequilibrium Green's function formalism (NEGF) [5][6][7][8][9][10][11][12] has enabled theoreticians to assist the above experiments with theoretical insights and predictions. However, the size and complexity of the experimentally active part of the junction is typically too large, and the above codes need to assume a number of simplifications regarding the size, geometry, number of feasible atomic arrangements, and the electronic correlations. Recently, some of the above codes have been combined with classical force field programs, enabling the simulation of much larger systems and the sampling of a much wider set of atomic arrangements. 13,14 Nevertheless, present current-voltage I -V characteristics are still computed using NEGF techniques, which are rather cumbersome and extremely computer hungry. In other words, the NEGF is a serious bottleneck hindering the deployment of realistic transport simulations at the nanoscale. In contrast, equilibrium transport techniques are much simpler, better founded on physical grounds, and computationally drastically less demanding. 6 However, they are completely unable to reproduce current-voltage curves of nanoscale devices. 15 This is so because these techniques assume that the electronic states and the Hamiltonian at the junction do not change under the application of a voltage. However, a voltage bias drives a flow of electrons into and out of the junction, driving the device out of equilibrium and possibly even changing its quantum state and sometimes even its atomic arrangement. For example, the electric field originated by the voltage bias can also shift the energy position of the molecular levels by the Stark effect, depending on the polarizability of each molecular level or on whether the molecule has itself a polar nature. 16,17 We show here a suitable modification of equilibrium transport te...