EPW Forum

Hi,

I noticed that all listed q-points have 0.0 as the component along x-axis. This doesn't seem correct for a 6x6x6 q-mesh.

Best,
Roxana

Dear Vahid,

The loop over ik should be "DO ik = 1, nksqtotf" same as when Sigma is written to file.

Best,
Roxana

Dear Cai, I would advise that you try to reproduce the results from the test directory EPW/tests/Refs/t05/paral The input parameters won't give you converged results, but you can directly check your output files with the references given. The input files are located in EPW/tests/Inputs/t05 Best, Rox...

Dear Ali, I found the following paragraph in QE user guide, where it is stated that ph.x code doesn't work with external electric fields. "The main code ph.x can be used whenever PWscf can be used, with the exceptions of: DFT+U, semiempirical VdW corrections, nonlocal vdW and hybrid functionals...

Dear Ali,

mp_mesh_k = .true. flag implies that symmetry is used in order to find the irreducible k-points.
You can try to see if removing this flag helps. However, I should point out that EPW has not been tested for a QE calculation in the presence of an electric field.

Best,
Roxana

Hi,

You need to make sure that the coarse k-mesh provided in the nscf calculation is strictly positive (x, y, and z components of each k point must be positive).

Best,
Roxana

Dear Vahid,

You need to make sure that you provide the exact same list of q-points as during the phonon calculations.

If everything match, it should work.

Best,
Roxana

Dear Vahid,

Did you generate the q-points in the same way when you did the phonon calculations to extract the dynamical matrices and deformation potential?

Best,
Roxana

Dear Ali, The number is column for needs to be divided by 512 (the total number of points). To check this use my first suggestion and run a scf calculations. I would also recommend that for questions related to QE you consult the QE tutorials and forum where you can find answers to many questions/pr...

Hi Ali,

You can simply run a scf calculations with your desired q-mesh and the coordinate and weight of each points is listed after "number of k points" line.

As an alternative you can use kpoints.f90 program that is provided in QE/PW/tools.


Best,
Roxana