Unknown VASP Error before entering SCF loop

[burakgurlek]

Hi,

I am simulating a rather small system with very demanding settings. I got 125 exit error from Slurm as you can see in the attachment. I tried to play with different parallelization schemas and reduced number of bands etc. but could not run more than 6min. It is likely that the memory is the issue but reducing the number of bands did not alleviate the problem.

Files.7z

I would appreciate the help

Regards,
Burak

[andreas.singraber]

Hello Burak,

I could reproduce this behavior and I am pretty sure that there is just not enough memory which needs to be allocated after some initialization period (6min in your case). Did you try to measure the memory usage for a simpler setup (less k-points, smaller ENCUT,...)?

Up until now I only performed rudimentary tests and I will need some more time to have a closer look. In the meantime, could you explain how you ended up with the current settings, in particular,

Code: Select all

PREC = High
ALGO = Exact
ENCUT = 1000
NBANDS = 1160

and also the k-points

Code: Select all

Automatic mesh
0              ! number of k-points = 0 ->automatic generation scheme
Gamma          ! generate a Gamma centered grid
24  4  6        ! subdivisions N_1, N_2 and N_3 along recipr. l. vectors
0. 0. 0.       ! shift of the mesh

Are you sure 24x4x6 is the right grid for the given structure? From the lattice vectors I would rather set something based on 4x2x1, i.e, the second number should be higher than the third one, right? Anyway, this may be unrelated to your problem.

All the best,
Andreas Singraber

[andreas.singraber]

Hello again!

I performed a few more tests to give you an impression on how the memory scales with the number of k-points and energy cutoff in your case. For this I used a machine with 1 TB of memory and started 32 MPI ranks. The setup is similar to yours, however, I used different k-grids and energy cutoffs. For each data point in the plot I ran VASP only until the memory consumption equilibrated. The k-point grids were

• 6 k-points: 4 x 2 x 1

• 36 k-points: 8 x 4 x 2

• 260 k-points: 16 x 8 x 4

mem-vs-encut-kpoints.png

As you can see there is no chance to run VASP with your current setup even on this 1 TB machine. Maybe you can make similar tests for your machine and see if there are some reduced settings which are still acceptable?

All the best,
Andreas Singraber