EPW Forum

Dear eliephys78, The python script is agnostic to your ph input file. Try cp the content of you OUT directory into the current one or re-run the ph with &inputph prefix = 'MgB2', fildyn = 'MgB2.dyn', amass(1) = 24.305, amass(2) = 10.811, outdir = './' ldisp = .true., trans = .true., fildvscf = '...

Dear Cai, Your input seems ok. Off course nkf and nqf grids needs to be increase to achieve convergence but you should get acceptable number already. Maybe try to increase wscut = 1.0 Also, when the numbers gets very large, it can create the ***** issue (depending on compiler). You can make the foll...

Dear Ali,

As stated by Roxana, EPW rely on el-ph matrix elements produced by QE.
We therefore support as much (or less) as QE/PH code supports.

In this case, EPW does not indeed support external electric field.

Best,

Samuel

Dear Vahid,

Thank you for reporting it.

I had done that for some of the examples and tests but obviously forgot some ..

Its now corrected.

Best,

Samuel

Dear Paul, Thank you for reporting that bug. I have changed in wigner_seitz.f90 and wigner_sietz2.f90: nind = 20*nk1*nk3*nk3 into nind = 20*nk1*nk2*nk3 I have commit the debug to the trunk of QE and credited you for it. This will be include in the next official release (sept 2016). Best, Samuel

Dear Vahid,

Thank you for reporting this.

I personally found, for example, a 30% speedup just by going from Intel 12 to 13 (with similar compilation flags).

Bottom line is that, yes, compiler and external libraries do matter.

Hi,

What is the error your are referring to in your last post?

The calculation stops after "Symmetries of crystal: 12" ?

Sam

Hi Giovanni,

Thank you again for reporting the outdir bug.

I have commit the debug to the trunk of QE.

One just need to add

as well as

in ephwan2blochp.f90

Best,

Samuel

Dear Derek, Thank you for reporting the issue and your extra testings. I will try to reproduce the NaN and debug. From my experience, impi is usually a bit faster than free alternatives like openmpi or mpich but somewhat more unstable. Currently EPW is tested the most with openmpi so you might look ...

Dear Vahid, Carla will for sure reply to this question better than me but from what I understand in the paper, it means: - Ground-state properties are computed on a 6x6x6 k-grid. This means the scf cycle. - Response properties are computed using DFPT using a 4x4x4 q-grid. This means the nscf.in is p...