In device calculations in ATK, usually scattering free transport is considered, and for devices it often gives NDR behavior.
However, the inclusion of phonons restores the conventional shape of the IV-curves (Mathieu Luisier talk at IEDM 2014 talk on MoS2 FET: 10.1109/IEDM.2014.7047142).
His work was based on eTB with multiple neighbours, the hamiltonian being constructed by Max.localizedWannier functions. This seems a promising approach, with great accuracy and flexibility too.
Can something similar not be implemented in ATK???