System don't Relax

[kazeej]

Hi,
I am running some DFT calculations on multi-component rare earth phosphates like (Lu0.5Sc0.5PO4). My system has failed to relax at all times I tried. What could be the reason for this?

Thanks.

[fabien_tran1]

Hi,

Please, read the guidelines:
forum/viewtopic.php?f=4&t=17928

You need to provide the files POSCAR and INCAR so that we can figure out what is the problem.

[kazeej]

Hello,

I have read from your suggestions but I still could not find a solution. I have attached my input files to this message.

Thanks.

POCC.zip

[fabien_tran1]

What do you mean with "system don't relax"? Is your calculation not running at all? Is it crashing? Is it not converging or very slowly? Is the output file OUTCAR generated?

[kazeej]

It is not converging. Or I would say it's taking lots of time. Jobs only run for 6 hours on our cluster and it doesn't converge within this time frame.

[fabien_tran1]

I have run your calculation and I can see that many SCF iterations (about 700) are required to reach convergence just for the initial geometry. At Category:Density_mixing there is some short explanation about mixing for convergence. Also, you may get some help from the forum by searching for the term "mixing".

Besides, I also recommend you to get more acquainted with VASP by running calculations on simpler systems as "exercises". This will also give you a better idea of the size of the systems that you can consider with your cluster.