Quantum mechanical effects are becoming increasingly important in realistic devices as their critical sizes reduce to a few nanometers. Equally important, yet not really appreciated is the ability to capture the details at the atomic level to capture effects of band-to-band mixing, band-non-parabolicities, and crystal orientations. The 1D hetero-structure tool presented here is based on the nearest neighbor tight-binding model (spds∗) that naturally captures these effects. The Non-equilibrium Green’s Function approach is used for transport calculations, in addition to the computation of electronic structure using a combination of numerical methods. Both open boundary conditions for arbitrary crystallographic orientations and closed boundary conditions can be applied. A sophisticated energy grid generation technology is employed that reduces simulation time and ensures that features are accurately captured without excessive compute times. The capabilities of the interactive simulator which will be deployed on nanoHUB.org are demonstrated. Introduction and approach It has been recognized for several years now, that effective mass models are inadequate to capture crucial details in devices with material variations at atomic dimensions. In addition to that a quantum-mechanical approach is necessary to explain the effects of geometry and Figure 1: Schematic drawing of a UTB band-structure. Here we use the spds∗ tight binding model to capture band-structure effects in 1D hetero-structures and demonstrate the capability of a simulator capable of handling various geometries in various materials. The model has been chosen since the s and p orbitals are enough to model the valence bands, and the excited d orbitals are necessary to model the conduction band over the entire Brillouin zone and to include the correct strain scaling behavior. In addition to that spin-orbit coupling is essential to get the correct valence bands.[2] Fig.1 shows schematically the kind of devices we are interested in modeling. The gate to substrate direction is the crystal growth direction which can be controlled at the atomic level. Compared to this direction where ma-