Phonon-assisted absorption calculation

sdwang · Post by **sdwang** » Tue Feb 19, 2019 2:27 pm

Dear all,
I have several questions about the phonon-assisted absorption calculations in EPW.
1). In order to reach converged results, one should take a supercell to calculate the dielectric function. If the primitcell
is big itself, how to take the supercell? I mean it would include huge atoms in this case.
2). For the force constants, the paper 'PHYSICAL REVIEW B 94, 075125 (2016)' claims that using just primitive cell. But when to do so, the number of atoms used here is different from the above step. How to understand this 2 step?

Thanks!

SD