Finite-displacement computation of the electron-phonon interaction within the projector augmented-wave method

A computational method has been developed to compute the electron-phonon interactions using the projector augmented wave method and finite displacements. Aluminium and diamond crystals are considered to test our strategy. It is found that the potential derivatives are quickly convergent with respect to the supercell size. Moreover the method is found to be efficient enough to densely sample the Brillouin zone and compute the Eliashberg function and phonon lifetime without requiring the use to interpolations.