EPW Forum

Dear Developers,

I recently encountered an error when running the EPW V5.4 code to calculate superconductivity properties. Specifically, I received an error message when attempting to use a grid size of nq=555, nk=555, nqf=101010, nkf=252525. This was unexpected, as I was able to conduct similar calculations with a smaller grid size of nq=444, nk=444, nqf=888, and nkf=161616 without issue.

I initially thought that this problem could be related to a lack of memory, so I tried using multiple nodes to distribute the calculation across a smaller number of cores, but this approach did not resolve the issue.

Could you please provide insight into why this error occurred and any suggestions as to how it can be resolved?

Thank you for your help.

===================================================================
irreducible q point # 27
===================================================================

Symmetries of small group of q: 4

Number of q in the star = 2
List of q in the star:
1 -0.140561626 0.000000000 0.000000000
2 0.140561626 0.000000000 0.000000000

q( 124 ) = ( -0.1405616 0.0000000 0.0000000 )
q( 125 ) = ( 0.1405616 0.0000000 0.0000000 )

Band disentanglement is used: nbndsub = 104
Use zone-centred Wigner-Seitz cells
Number of WS vectors for electrons 141
Number of WS vectors for phonons 141
Number of WS vectors for electron-phonon 141
Maximum number of cores for efficient parallelization 12690
Results may improve by using use_ws == .TRUE.

Velocity matrix elements calculated


%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%
Error in routine diropn (116):
error opening ./BC.epmatwe1
%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%

stopping ..

Dear hou:

Your error indicates that there are issues with opening the file.
Could you show us the full input and output of EPW?
In addition, could you show us the full list of files and directories under the current working directory?

Sincerely,

H. Lee