EPW Forum

Dear H. Lee, Thank you for weighing in! I have a few follow-up questions: 1) Is there another way of fixing this error short of fully repeating the calculation? For instance, would it be possible to regenerate the ephmat files from other files on disk, without running the full q-grid interpolation a...

Dear Hari, Thank you very much for your suggestions! I know that the calculation was able to run when the fine q-grid was 8*8*4 instead of 16*16*8. However, unfortunately I didn't save the ephmat files from that run, so I don't know what their sizes were. I have run a related calculation though, wit...

Hello, I have a fairly large system with 24 hydrogen atoms. I'm able to run the q-grid interpolation with success, using 128 processors on 32 nodes, but when the calculation gets to the calculation of the Eliashberg spectral function, it crashes after the line that says "Start reading .ephmat files"...

Dear H. Lee,

Thank you very much! After striping the large files, my access to the queues has been restored, and hopefully further issues will be avoided.

Best,
Mehmet

Hello, I'm running EPW on the TACC Frontera supercomputer. While running a q-point interpolation on 32 nodes and 128 processors, my job was canceled by system admins, due to "an OSS server overloading while reading a very large file from many tasks". The file in question is the epmatwp file whose si...

Dear H. Lee, Thank you very much for your reply! Actually, when the calculation kept going, it indeed picked up from where it had left off in the q-point interpolation. I was confused because it was repeating the earlier stages of the calculation (Wannierization, e-ph coupling) and thought that rest...

PS. I'm using EPW 5.3.0 that came with QE 6.6.

Hello, I'm an EPW novice, and have a basic question about restarting the calculation. I'm trying to interpolate the e-ph matrix elements onto a fine q-grid, and the calculation will take a few walltimes (input file below). I found a few forum posts about how to restart this calculation but wasn't su...

Dear H. Lee,

Thank you very much! I will try these things as soon as I am able to run calculations again on Frontera, which unfortunately is reserved for a week for large-scale jobs (1000s of nodes). I will let you know what happens. Thank you!

Best,
Mehmet

Dear H. Lee, Thank you very much for your advice! It's unfortunate that I might have to consult my system administrator, which is usually a very slow process. I'd like to try a couple of things before submitting a help ticket. 1) Do you think simply increasing the number of nodes might solve this pr...