Error: Calculation not providing result

[physics]

Hi,

I am calculating band structure of a hetero structure but the calculation is not stopping and running from 4 days. Please help me. I am attaching screenshot of my settings.

Thanks

[AsifShah]

Open log file and go to end, take the screenshot and share.

[physics]

Hi,

PFA the screeshots of log file which I obtained by changing node, core, time parameters. But my calculations are still running and I am not getting output (trying to obtain bandstructure).

Thanks

[AsifShah]

1. How many atoms do you have in your system?
2. Why arent you running calculation using MPI? Are you running it on single core?
The first screenshot looks like memory issue.

[physics]

1. There are 1188 atoms.
2. I am using 8 cores per node.

For memory issue, I started submitting the job on server instead of running in my own computer. Even though I am using server, the calculations are not providing output. Recently, I got the below error (screenshot attached) saying about time issue. I am using 100 h. It will be great if you could help.

[Anders Blom]

This is a big job, it will take time. You can however redo the band structure now, there is no need to redo the self-consistent loop. Only using 1 node, even with 8 cores, is quite limited, I would try to either use more cores on that single node, or more nodes. Basically the band structure calculation will scale linearly with the total number of cores.

[physics]

Thank you for the reply. How to calculate band structure without redo of self consistent loop? Please advise.

[Anders Blom]

If you are ok with scripting, it's pretty easy to explain. It's also very easy using the GUI, but harder to explain in text...

My recommendation would be to take your Python script that you were running and make a copy of it.

Then locate the line which says something like bulk_configuration.update() - this is the line that triggers the self-consistent calculation. Right after that, you should see a line with "nlsave", which saves the converged state of the calculation once it's done.

Now it's hard to understand what to do. We basically just need to read this state from the file, instead of re-running. After that, all the following lines will work the same.

So, comment out the "update" and "nlsave" lines, and replace them with

bulk_configuration = nlread(filename, BulkConfiguration)[-1]

Note that you need to change the filename to match your case, and also check that the variable was bulk_configuration, sometimes it's different. But just take it from the lines you comment out.

[physics]

Thank you for reply. I will try this.

[AsifShah]

I hope your problem is solved.
But just a question, why do u have so many atoms in your system?
You can design a smaller heterostructure of your system using interface builder that will bring down the number of atoms and time consumed.
This won't change physics if your system is pristine.

[physics]

I got the minimum strain for this system. If I was decreasing the number of atoms, then the strain was increasing a lot. If you have any suggestion on this issue, please guide.

[AsifShah]

I don't know how strain will affect your study, but I have would say a 2% strain is okay. However, I would suggest looking into the literature to see how much strain people use in similar work as that of yours.

I am guessing you are reducing strain below 1% or 0.5% which is why you have so many atoms in your system.

[physics]

Hi,

I will try to build new interface. Thank you.