Dear esteemed professors and researchers,

I am a master's student currently exploring electronic transport properties using Quantum ESPRESSO and EPW.

My research focuses on phonon mode contributions to electron and hole transport, particularly in a hexagonal boron nitride (h-BN) monolayer.

I am attempting to compute the mode-resolved phonon scattering rates of h-BN, but I have encountered a challenge:

the EPW output provides information about the phonon modes only as numerical indices (i.e., imode), without distinguishing them as LA, TA, ZA, LO, TO and ZO mode.

Below is an excerpt of the EPW output for reference:

# Hole relaxation time [Multiply the relaxation time by 20670.6944033 to get 1/ps]

# itemp kpt ibnd imode energy [Ry] relaxation time [Ry]

1 1 1 1 -0.810490382040E+00 0.625111293883E-03

1 1 1 2 -0.810490382040E+00 0.212550468286E-03

1 1 1 3 -0.810490382040E+00 0.130978893977E-02

1 1 1 4 -0.810490382040E+00 0.134330067897E-04

1 1 1 5 -0.810490382040E+00 0.260869373606E-01

1 1 1 6 -0.810490382040E+00 0.289329622319E-01

I understand from the EPW forum discussions

(https://forum.epw-code.org/viewtopic.php?t=1340) that the code currently does not provide direct output to map the modes (LA, TA, ZA, LO, TO, ZO) in this context.

I would be deeply grateful if anyone could share insights into how I might approach this problem or clarify the core concepts. Specifically, is there a method to link the imode indices in the EPW output to specific phonon modes?

I would appreciate detailed guidance if any modifications or additional post-processing steps are required.

For further context, I have attached the QE and EPW input files used for my calculations.

Thank you very much for your time and consideration. I am eager to learn from your expertise!

Sincerely, Dai-Chan Hu