  A computationally efficient workflow for obtaining low-energy tight-binding
Hamiltonians for twisted bilayer graphene, obeying both crystal and
time-reversal symmetries, is presented in this work. The Hamiltonians at the
first magic angle are generated using the Slater-Koster approach with
parameters obtained by a fit to ab-initio data at larger angles. Low-energy
symmetric four-band and twelve-band Hamiltonians are constructed using the
Wannier90 software. The advantage of our scheme is that the low-energy
Hamiltonians are purely real and are obtained with the maximum-localization
procedure to reduce the spread of the basis functions. Finally, we compute
extended Hubbard parameters for both models within the constrained random phase
approximation (cRPA) for screening, which again respect the symmetries. The
relevant data and results of this work are freely available via an online
repository. The workflow is straightforwardly transferable to other twisted
multi-layer materials.
