we are currently calculating the EPC of a nonpolar structure and are wondering if our coarse phonon mesh is sufficiently converged. Below you can see the decay.epmatp for a coarse 4x4x4 q-mesh, which decays quite nicely by almost three orders of magnitude. Checking convergence with a much more expensive 8x8x8 q-mesh does not seem to improve the decay in any way, or what can we learn from the flattening of the points? It may be worth mentioning that those calculations are without LO/TO-splitting, as it is a doped system. In the undoped system, LO/TO-splitting has quite large influence on the Gamma modes.
Any opinion on this decay topic or comment if using just the 4x4x4 mesh will lead to reasonable qualitative results on the phonon-mode-resolved lambda is highly appreciated!
Best regards,
Tobias