  Here we demonstrate workably accurate estimation of optical excitation
threshold for large systems comprising of hundreds of atoms through an
anti-causally corrected(ACC) real-time dynamics(RTD) approach implemented in a
minimal tight-binding basis constituted by the directed hybrid atomic Wannier
orbitals. A correction to the Hamiltonian is applied anti-causally at all time
steps to account for electron-hole interaction using the density-density
response function. Minimality of basis and ease of transferability of
parameters to large systems arises from the directed nature of the Wannierized
hybrid basis orbitals used.With self-energy corrected TB parameters evaluated
at the DFT + G 0 W 0 level, the proposed ACC-RTD scheme can be systematically
parametrized to render optical excitation threshold for systems of
experimentally realizable length-scales through inexpensive computation.
