  A computationally efficient workflow for obtaining the low-energy symmetric
tight-binding Hamiltonians for twisted multilayer systems is presented in this
work. We apply this scheme to twisted bilayer graphene at the first magic
angle. As initial step, the full-energy tight-binding Hamiltonian is generated
by the Slater-Koster model with parameters fitted to ab-initio data at larger
angles. Then, the low-energy symmetric four-band and twelve-band Hamiltonians
are constructed using the maximum-localization procedure subjected to crystal
and time-reversal-symmetry constraints. 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. Our
workflow, exemplified in this work on twisted bilayer graphene, is
straightforwardly transferable to other twisted multi-layer materials.
